PHYSREPositoryhttps://physrep.ff.bg.ac.rsThe DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material.Thu, 14 Nov 2024 12:02:56 GMT2024-11-14T12:02:56Z50531- Landau levels from noncommutative U (1) ∗ gauge theory in κ -Minkowski space-timehttps://physrep.ff.bg.ac.rs/handle/123456789/247Title: Landau levels from noncommutative U (1) ∗ gauge theory in κ -Minkowski space-time
Authors: Dimitrijević-Ćirić, Marija; Konjik, Nikola
Abstract: Motivated by physics of the Lowest Landau Level and the Quantum Hall Effect, we investigate motion of an electron in a constant background magnetic field in the κ-Minkowski space-time. Starting from an action invariant under the noncommutative U(1) gauge transformations, we obtain the κ-deformed Dirac equation. Using the perturbative approach, we calculate noncommutative corrections to energy levels, mass and the gyromagnetic ratio up to the first order in the deformation parameter a = 1/ κ.
Wed, 01 Aug 2018 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/2472018-08-01T00:00:00Z
- U(1) gauge field theory on κ-Minkowski spacehttps://physrep.ff.bg.ac.rs/handle/123456789/275Title: U(1) gauge field theory on κ-Minkowski space
Authors: Dimitrijević-Ćirić, Marija; Jonke, Larisa; Moller, Lutz
Abstract: This study of U(1) gauge field theory on the kappa-deformed Minkowski space-time extends previous work on gauge field theories on this type of noncommutative space-time.We construct the conserved gauge current, fix part of the ambiguities in the Seiberg-Witten map and obtain an effective U(1) action invariant under the action of the undeformed Poincare group. © Institute of Physics, Academy of Sciences of Czech Republic 2005.
Tue, 01 Nov 2005 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/2752005-11-01T00:00:00Z
- Another example of noncommutative spaces: κ-deformed spacehttps://physrep.ff.bg.ac.rs/handle/123456789/267Title: Another example of noncommutative spaces: κ-deformed space
Authors: Dimitrijević-Ćirić, Marija
Abstract: In this chapter we discuss another type of noncommutative space, the κ-deformed space. It is an example of Lie algebra type of deformation of the usual commutative space. In the first part derivatives and the symmetry of this space are discussed. We start with the abstract algebra of operators and using the - product approach represent everything on the space of commuting coordinates. In the second part we describe how to construct noncommutative gauge theory on this space using the Seiberg-Witten approach. © 2009 Springer.
Fri, 04 Sep 2009 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/2672009-09-04T00:00:00Z
- Erratum: Generalized Bloch theorem and topological characterization (Phys. Rev. B (2015) 91 (125424))https://physrep.ff.bg.ac.rs/handle/123456789/270Title: Erratum: Generalized Bloch theorem and topological characterization (Phys. Rev. B (2015) 91 (125424))
Authors: Dobardžić, Edib; Dimitrijević-Ćirić, Marija; Milovanović, M. V.
Mon, 16 Nov 2015 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/2702015-11-16T00:00:00Z
- SO(2, 3) noncommutative gravity modelhttps://physrep.ff.bg.ac.rs/handle/123456789/268Title: SO(2, 3) noncommutative gravity model
Authors: Dimitrijević-Ćirić, Marija; Radovanović, Voja
Abstract: In this paper the noncommutative gravity is treated as a gauge theory of the non-commutative SO(2, 3)★ group, while the noncommutativity is canonical. The Seiberg-Witten (SW) map is used to express noncommutative fields in terms of the corresponding commutative fields. The commutative limit of the model is the Einstein-Hilbert action plus the cosmological term and the topological Gauss-Bonnet term. We calculate the second order correction to this model and obtain terms that are zeroth, first,.. and fourth power of the curvature tensor. Finally, we discuss physical consequences of those correction terms in the limit of big cosmological constant.
Wed, 01 Jan 2014 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/2682014-01-01T00:00:00Z
- Non(anti)commutative Field Theories: Model Building and renormalizability propertieshttps://physrep.ff.bg.ac.rs/handle/123456789/244Title: Non(anti)commutative Field Theories: Model Building and renormalizability properties
Authors: Dimitrijević-Ćirić, Marija; Nikolić, Biljana; Radovanović, Voja
Abstract: We discuss one particular model of non(anti)commutative superspace. The deformation is nonhermitian and given in terms of the SUSY covariant derivatives D α. We construct a deformed Wess-Zumino action and analyze its renormalizability properties. One-loop divergences in the twopoint, three-point and four-point Green functions are calculated. In the general model we find that divergences in the four-point function cannot be absorbed and thus our model is not renormalizable. However, there is a special choice of the free parameters in the model that renders renormalizability. We discuss this choice and other possibilities to render the model renormalizable.
Thu, 01 Dec 2011 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/2442011-12-01T00:00:00Z
- Deformed gauge theory: Twist versus Seiberg-Witten approachhttps://physrep.ff.bg.ac.rs/handle/123456789/265Title: Deformed gauge theory: Twist versus Seiberg-Witten approach
Authors: Dimitrijević-Ćirić, Marija
Abstract: In this chapter we discuss two possible ways of introducing gauge theories on noncommutative spaces. In the first approach the algebra of gauge transformations is unchanged, but the Leibniz rule is changed (compared with gauge theories on commutative space). Consistency of the equations of motion requires enveloping algebravalued gauge fields, which leads to new degrees of freedom. In the second approach we have to go to the enveloping algebra again if we want noncommutative gauge transformations to close in the algebra. However, no new degrees of freedom appear here because of the Seiberg-Witten map. This map enables one to express noncommutative gauge parameters and fields in terms of the corresponding commutative variables. © 2009 Springer.
Thu, 03 Sep 2009 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/2652009-09-03T00:00:00Z
- SO(2,3)<inf>★</inf> Noncommutative Gravity: Coupling with Matter Fieldshttps://physrep.ff.bg.ac.rs/handle/123456789/75Title: SO(2,3)<inf>★</inf> Noncommutative Gravity: Coupling with Matter Fields
Authors: Dimitrijević-Ćirić, Marija; Gočanin, Dragoljub; Konjik, Nikola; Radovanović, Voja
Abstract: Abstract: In this paper, noncommutative gravity is treated as a gauge theory of the noncommutative SO(2,3)★ group, while the noncommutativity is canonical. The Seiberg–Witten (SW) map is used to express noncommutative fields in terms of the corresponding commutative fields. In addition to pure gravity, we consider couplings to matter fields, in particular, to the Dirac and U(1) gauge field. The analysis can be extended to non Abelian gauge fields and scalar fields.
Sat, 01 Sep 2018 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/752018-09-01T00:00:00Z
- Renormalizability of the D-deformed Wess-Zumino modelhttps://physrep.ff.bg.ac.rs/handle/123456789/250Title: Renormalizability of the D-deformed Wess-Zumino model
Authors: Dimitrijević-Ćirić, Marija; Nikolić, Biljana; Radovanović, Voja
Abstract: We discuss a deformation of superspace which is defined using the twist formalism. The twist we use is nonhermitian and it is given in terms of the covariant derivatives Dα. We calculate one-loop divergences in the two-point, three-point and four-point Green functions. Possibilities to render the model renormalizable are discussed.
Thu, 28 Jun 2012 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/2502012-06-28T00:00:00Z
- Noncommutative gravity via SO(2;3) noncommutative Gauge theoryhttps://physrep.ff.bg.ac.rs/handle/123456789/22Title: Noncommutative gravity via SO(2;3) noncommutative Gauge theory
Authors: Dimitrijević-Ćirić, Marija; Radovanović, Voja
Abstract: In this paper the noncommutative gravity is treated as a gauge theory of the noncommutative SO(2; 3)* group on the noncommutative space with the constant noncommutativity. The enveloping algebra approach and the Seiberg-Witten map are used to relate noncommutative and the commutative gauge theory. By combining different actions a noncommutative gravity model is constructed in such a way that the cosmological constant term is not present in the commutative limit, but it is generated by the noncommutativity and it appears in the higher order expansion. We calculate the second order correction to this model and obtain terms that are zero-th, first, . . . and fourth power of the curvature tensor. Finally, we discuss physical consequences of those correction terms in the low energy limit.
Fri, 01 Jan 2016 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/222016-01-01T00:00:00Z
- Field theory on nonanticommutative superspacehttps://physrep.ff.bg.ac.rs/handle/123456789/249Title: Field theory on nonanticommutative superspace
Authors: Dimitrijević-Ćirić, Marija; Radovanović, Voja; Wess, Julius
Abstract: We discuss a deformation of the Hopf algebra of supersymmetry (SUSY) transformations based on the special choice of twist. As usual, algebra itself remains unchanged, but the comultiplication changes. This leads to the deformed Leibniz rule for SUSY transformations. Superfields are elements of the algebra of functions of the usual supercoordinates. Elements of this algebra are multiplied by using the -product which is noncommutative, hermitian and finite when expanded in power series of the deformation parameter. Chiral fields are no longer a subalgebra of the algebra of superfields. One possible deformation of the Wess-Zumino action is proposed and analyzed in detail. Differently from most of the literature concerning this subject, we work in Minkowski space-time. © SISSA 2007.
Sat, 01 Dec 2007 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/2492007-12-01T00:00:00Z
- A twisted look on kappa-Minkowski: U(1) gauge theoryhttps://physrep.ff.bg.ac.rs/handle/123456789/263Title: A twisted look on kappa-Minkowski: U(1) gauge theory
Authors: Dimitrijević-Ćirić, Marija; Jonke, Larisa
Abstract: Kappa-Minkowski space-time is an example of noncommutative space-time with potentially interesting phenomenological consequences. However, the construction of field theories on this space, although operationally well-defined, is plagued with ambiguities. A part of ambiguities can be resolved by clarifying the geometrical picture of gauge transformations on the κ-Minkowski space-time. To this end we use the twist approach to construct the noncommutative U(1) gauge theory coupled to fermions. However, in this approach we cannot maintain the kappa-Poincaré symmetry; the corresponding symmetry of the twisted kappa-Minkowski space is the twisted igl(1,3) symmetry. We construct an action for the gauge and matter fields in a geometric way, as an integral of a maximal form. We use the Seiberg-Witten map to relate noncommutative and commutative degrees of freedom and expand the action to obtain the first order corrections in the deformation parameter. © SISSA 2011.
Wed, 28 Dec 2011 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/2632011-12-28T00:00:00Z
- Twisted supersymmetry: Twisted symmetry versus renormalizabilityhttps://physrep.ff.bg.ac.rs/handle/123456789/243Title: Twisted supersymmetry: Twisted symmetry versus renormalizability
Authors: Dimitrijević-Ćirić, Marija; Nikolić, Biljana; Radovanović, Voja
Abstract: We discuss a deformation of superspace based on a Hermitian twist. The twist implies a -product that is noncommutative, Hermitian and finite when expanded in a power series of the deformation parameter. The Leibniz rule for the twisted supersymmetry transformations is deformed. A minimal deformation of the Wess-Zumino action is proposed and its renormalizability properties are discussed. There is no tadpole contribution, but the two-point function diverges. We speculate that the deformed Leibniz rule, or more generally the twisted symmetry, interferes with renormalizability properties of the model. We discuss different possibilities to render a renormalizable model. © 2011 American Physical Society.
Mon, 07 Mar 2011 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/2432011-03-07T00:00:00Z
- Noncommutative scalar quasinormal modes of the Reissner-Nordström black holehttps://physrep.ff.bg.ac.rs/handle/123456789/246Title: Noncommutative scalar quasinormal modes of the Reissner-Nordström black hole
Authors: Dimitrijević-Ćirić, Marija; Konjik, Nikola; Samsarov, Andjelo
Abstract: Aiming to search for a signal of space-time noncommutativity, we study a quasinormal mode spectrum of the Reissner-Nordstrom black hole in the presence of a deformed space-time structure. In this context we study a noncommutative (NC) deformation of a scalar field, minimally coupled to a classical (commutative) Reissner-Nordstrom background. The deformation is performed via a particularly chosen Killing twist to ensure that the geometry remains undeformed (commutative). An action describing a noncommutative scalar field minimally coupled to the RN geometry is manifestly invariant under the deformed U(1)∗ gauge symmetry group. We find the quasinormal mode solutions of the equations of motion governing the matter content of the model in some particular range of system parameters which corresponds to a near extremal limit. In addition, we obtain a well defined analytical condition which allows for a detailed numerical analysis. Moreover, there exists a parameter range, rather restrictive though, which allows for obtaining a QNMs spectrum in a closed analytic form. We also argue within a semiclassical approach that NC deformation does not affect the Hawking temperature of thermal radiation.
Wed, 25 Jul 2018 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/2462018-07-25T00:00:00Z
- Quantization of gauge theory on a curved noncommutative spacehttps://physrep.ff.bg.ac.rs/handle/123456789/213Title: Quantization of gauge theory on a curved noncommutative space
Authors: Burić, Maja; Dimitrijević-Ćirić, Marija; Radovanović, Voja; Wohlgenannt, M.
Abstract: We study quantization of a gauge analogon of the Grosse-Wulkenhaar scalar field model. We calculate divergent first-order one-loop contributions to the tadpoles and the propagators: we find that there are no UV divergences while all IR divergences are logarithmic. Divergent terms which we obtain can be included in the initial action either by a shift of the vacuum or by adding the Chern-Simons term. Our results, though partial, indicate renormalizability: they need to be complemented by calculation of the second-order divergent contributions to the propagators and vertices. © 2012 American Physical Society.
Fri, 16 Nov 2012 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/2132012-11-16T00:00:00Z
- Microscopic derivation of Dirac composite fermion theory: Aspects of noncommutativity and pairing instabilitieshttps://physrep.ff.bg.ac.rs/handle/123456789/19Title: Microscopic derivation of Dirac composite fermion theory: Aspects of noncommutativity and pairing instabilities
Authors: Gočanin, Dragoljub; Predin, Sonja; Dimitrijević-Ćirić, Marija; Radovanović, Voja; Milovanović, Milica
Abstract: Building on previous work [N. Read, Phys. Rev. B58, 16262 (1998)10.1103/PhysRevB.58.16262; Z. Dong and T. Senthil, Phys. Rev. B102, 205126 (2020)10.1103/PhysRevB.102.205126] on the system of bosons at filling factor , we derive the Dirac composite fermion theory for a half-filled Landau level from first principles and apply the Hartree-Fock approach in a preferred representation. On the basis of the microscopic formulation, in the long-wavelength limit, we propose a noncommutative field-theoretical description, which in a commutative limit reproduces the Son's theory, with additional terms that may be expected on physical grounds. The microscopic representation of the problem is also used to discuss pairing instabilities of composite fermions. We find that a presence of a particle-hole symmetry breaking leads to a weak (BCS) coupling -wave pairing in the lowest Landau level, and strong coupling -wave pairing in the second Landau level that occurs in a band with nearly flat dispersion, a third power function of momentum.
Wed, 15 Sep 2021 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/192021-09-15T00:00:00Z
- (Non)renormalizability of the D-deformed Wess-Zumino modelhttps://physrep.ff.bg.ac.rs/handle/123456789/240Title: (Non)renormalizability of the D-deformed Wess-Zumino model
Authors: Dimitrijević-Ćirić, Marija; Nikolić, Biljana; Radovanović, Voja
Abstract: We continue the analysis of the D-deformed Wess-Zumino model that we introduced in M. Dmitrijevic and V. Radovanovic, J. High Energy Phys. 04 (2009) 108. The model is defined by a deformation that is non-Hermitian and given in terms of the covariant derivatives Dα. We calculate one-loop divergences in the two-point, three-point, and four-point Green functions. Possibilities to render the model renormalizable are discussed. © 2010 The American Physical Society.
Thu, 20 May 2010 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/2402010-05-20T00:00:00Z
- Derivatives, forms and vector fields on the κ-deformed Euclidean spacehttps://physrep.ff.bg.ac.rs/handle/123456789/258Title: Derivatives, forms and vector fields on the κ-deformed Euclidean space
Authors: Dimitrijević-Ćirić, Marija; Möller, Lutz; Tsouchnika, Efrossini
Abstract: The model of κ-deformed space is an interesting example of a noncommutative space, since it allows a deformed symmetry. In this paper, we present new results concerning different sets of derivatives on the coordinate algebra of κ-deformed Euclidean space. We introduce a differential calculus with two interesting sets of one-forms and higher-order forms. The transformation law of vector fields is constructed in accordance with the transformation behaviour of derivatives. The crucial property of the different derivatives, forms and vector fields is that in an n-dimensional spacetime there are always n of them. This is the key difference with respect to conventional approaches, in which the differential calculus is (n + 1)-dimensional. This work shows that derivative-valued quantities such as derivative-valued vector fields appear in a generic way on noncommutative spaces.
Fri, 15 Oct 2004 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/2582004-10-15T00:00:00Z
- Noncommutative gravity at second order via Seiberg-Witten maphttps://physrep.ff.bg.ac.rs/handle/123456789/269Title: Noncommutative gravity at second order via Seiberg-Witten map
Authors: Aschieri, Paolo; Castellani, Leonardo; Dimitrijević-Ćirić, Marija
Abstract: We develop a general strategy to express noncommutative actions in terms of commutative ones by using a recently developed geometric generalization of the Seiberg-Witten map between noncommutative and commutative fields. We apply this general scheme to the noncommutative vierbein gravity action and provide a Seiberg-Witten differential equation for the action itself as well as a recursive solution at all orders in the noncommutativity parameter θ. We thus express the action at order θn+2 in terms of noncommutative fields of order at most θn+1 and, iterating the procedure, in terms of noncommutative fields of order at most θn. This in particular provides the explicit expression of the action at order θ2 in terms of the usual commutative spin connection and vierbein fields. The result is an extended gravity action on commutative spacetime that is manifestly invariant under local Lorentz rotations and general coordinate transformations. © 2013 American Physical Society.
Tue, 08 Jan 2013 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/2692013-01-08T00:00:00Z
- Gauge theory on twisted κ-Minkowski: Old problems and possible solutionshttps://physrep.ff.bg.ac.rs/handle/123456789/259Title: Gauge theory on twisted κ-Minkowski: Old problems and possible solutions
Authors: Dimitrijević-Ćirić, Marija; Jonke, Larisa; Pachoł, Anna
Abstract: We review the application of twist deformation formalism and the construction of noncommutative gauge theory on κ-Minkowski space-time. We compare two different types of twists: the Abelian and the Jordanian one. In each case we provide the twisted differential calculus and consider U(1) gauge theory. Different methods of obtaining a gauge invariant action and related problems are thoroughly discussed.
Sat, 14 Jun 2014 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/2592014-06-14T00:00:00Z
- Nonassociative differential geometry and gravity with non-geometric fluxeshttps://physrep.ff.bg.ac.rs/handle/123456789/239Title: Nonassociative differential geometry and gravity with non-geometric fluxes
Authors: Aschieri, Paolo; Dimitrijević-Ćirić, Marija; Szabo, Richard J.
Abstract: We systematically develop the metric aspects of nonassociative differential geometry tailored to the parabolic phase space model of constant locally non-geometric closed string vacua, and use it to construct preliminary steps towards a nonassociative theory of gravity on spacetime. We obtain explicit expressions for the torsion, curvature, Ricci tensor and Levi-Civita connection in nonassociative Riemannian geometry on phase space, and write down Einstein field equations. We apply this formalism to construct R-flux corrections to the Ricci tensor on spacetime, and comment on the potential implications of these structures in non-geometric string theory and double field theory.
Thu, 01 Feb 2018 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/2392018-02-01T00:00:00Z
- Noncommutative geometry and gravityhttps://physrep.ff.bg.ac.rs/handle/123456789/256Title: Noncommutative geometry and gravity
Authors: Aschieri, Paolo; Dimitrijević-Ćirić, Marija; Meyer, Frank; Wess, Julius
Abstract: We study a deformation of infinitesimal diffeomorphisms of a smooth manifold. The deformation is based on a general twist. This leads to a differential geometry on a noncommutative algebra of functions whose product is a star product. The class of noncommutative spaces studied is very rich. Non-anticommutative superspaces are also briefly considered. The differential geometry developed is covariant under deformed diffeomorphisms and is coordinate independent. The main target of this work is the construction of Einstein's equations for gravity on noncommutative manifolds. © 2006 IOP Publishing Ltd.
Tue, 21 Mar 2006 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/2562006-03-21T00:00:00Z
- Noncommutative so (2, 3)∗ gravity: Noncommutativity as a source of curvature and torsionhttps://physrep.ff.bg.ac.rs/handle/123456789/238Title: Noncommutative so (2, 3)∗ gravity: Noncommutativity as a source of curvature and torsion
Authors: Dimitrijević-Ćirić, Marija; Nikolić, Biljana; Radovanović, Voja
Abstract: Noncommutative (NC) gravity is constructed on the canonical noncommutative (Moyal-Weyl) spacetime as a noncommutative SO(2,3) gauge theory. The NC gravity action consists of three different terms: the first term is of Mac-Dowell Mansouri type, while the other two are generalizations of the Einstein-Hilbert action and the cosmological constant term. The expanded NC gravity action is then calculated using the Seiberg-Witten (SW) map and the expansion is done up second order in the deformation parameter. We analyze in details the low energy sector of the full model. We calculate the equations of motion, discuss their general properties and present one solution: the NC correction to Minkowski spacetime. Using this solution, we explain breaking of the diffeomorphism symmetry as a consequence of working in a particular coordinate system given by the Fermi normal coordinates.
Mon, 18 Sep 2017 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/2382017-09-18T00:00:00Z
- Twisted gauge theorieshttps://physrep.ff.bg.ac.rs/handle/123456789/260Title: Twisted gauge theories
Authors: Aschieri, Paolo; Dimitrijević-Ćirić, Marija; Meyer, Frank; Schraml, Stefan; Wess, Julius
Abstract: Gauge theories on a space-time that is deformed by the Moyal-Weyl product are constructed by twisting the coproduct for gauge transformations. This way a deformed Leibniz rule is obtained, which is used to construct gauge invariant quantities. The connection will be enveloping algebra valued in a particular representation of the Lie algebra. This gives rise to additional fields, which couple only weakly via the deformation parameter θ and reduce in the commutative limit to free fields. Consistent field equations that lead to conservation laws are derived and some properties of such theories are discussed. © Springer Science+Business Media, Inc. 2006.
Sun, 01 Jan 2006 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/2602006-01-01T00:00:00Z
- Noncommutative field theory from angular twisthttps://physrep.ff.bg.ac.rs/handle/123456789/248Title: Noncommutative field theory from angular twist
Authors: Dimitrijević-Ćirić, Marija; Konjik, Nikola; Kurkov, Maxim A.; Lizzi, Fedele; Vitale, Patrizia
Abstract: We consider a noncommutative field theory in three space-time dimensions, with space-time star commutators reproducing a solvable Lie algebra. The -product can be derived from a twist operator and it is shown to be invariant under twisted Poincaré transformations. In momentum space the noncommutativity manifests itself as a noncommutative -deformed sum for the momenta, which allows for an equivalent definition of the -product in terms of twisted convolution of plane waves. As an application, we analyze the λφ4 field theory at one loop and discuss its UV/IR behavior. We also analyze the kinematics of particle decay for two different situations: the first one corresponds to a splitting of space-time where only space is deformed, whereas the second one entails a nontrivial -multiplication for the time variable, while one of the three spatial coordinates stays commutative.
Mon, 15 Oct 2018 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/2482018-10-15T00:00:00Z
- Deformed field theory on κ-spacetimehttps://physrep.ff.bg.ac.rs/handle/123456789/271Title: Deformed field theory on κ-spacetime
Authors: Dimitrijević-Ćirić, Marija; Jonke, L.; Möller, L.; Tsouchnika, E.; Wess, J.; Wohlgenannt, M.
Abstract: A general formalism is developed that allows the construction of a field theory on quantum spaces which are deformations of ordinary spacetime. The symmetry group of spacetime (the Poincaré group) is replaced by a quantum group. This formalism is demonstrated for the κ-deformed Poincaré algebra and its quantum space. The algebraic setting is mapped to the algebra of functions of commuting variables with a suitable *-product. Fields are elements of this function algebra. The Dirac and Klein-Gordon equation are defined and an action is found from which they can be derived.
Wed, 01 Jan 2003 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/2712003-01-01T00:00:00Z
- Braided L<inf>∞</inf> -algebras, braided field theory and noncommutative gravityhttps://physrep.ff.bg.ac.rs/handle/123456789/899Title: Braided L<inf>∞</inf> -algebras, braided field theory and noncommutative gravity
Authors: Dimitrijević-Ćirić, Marija; Giotopoulos, Grigorios; Radovanović, Voja; Szabo, Richard J.
Abstract: We define a new homotopy algebraic structure, that we call a braided L∞-algebra, and use it to systematically construct a new class of noncommutative field theories, that we call braided field theories. Braided field theories have gauge symmetries which realize a braided Lie algebra, whose Noether identities are inhomogeneous extensions of the classical identities, and which do not act on the solutions of the field equations. We use Drinfel’d twist deformation quantization techniques to generate new noncommutative deformations of classical field theories with braided gauge symmetries, which we compare to the more conventional theories with star-gauge symmetries. We apply our formalism to introduce a braided version of general relativity without matter fields in the Einstein–Cartan–Palatini formalism. In the limit of vanishing deformation parameter, the braided theory of noncommutative gravity reduces to classical gravity without any extensions.
Wed, 01 Dec 2021 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/8992021-12-01T00:00:00Z
- Noncommutative so (2,3) gauge theory and noncommutative gravityhttps://physrep.ff.bg.ac.rs/handle/123456789/252Title: Noncommutative so (2,3) gauge theory and noncommutative gravity
Authors: Dimitrijević-Ćirić, Marija; Radovanović, Voja
Abstract: In this paper noncommutative gravity is constructed as a gauge theory of the noncommutative SO(2,3) group, while the noncommutativity is canonical (constant). The Seiberg-Witten map is used to express noncommutative fields in terms of the corresponding commutative fields. The commutative limit of the model is the Einstein-Hilbert action with the cosmological constant term and the topological Gauss-Bonnet term. We calculate the second order correction to this model and obtain terms that are of zeroth to fourth power in the curvature tensor and torsion. Trying to relate our results with f(R) and f(T) models, we analyze different limits of our model. In the limit of big cosmological constant and vanishing torsion we obtain an x-dependent correction to the cosmological constant; i.e. noncommutativity leads to an x-dependent cosmological constant. We also discuss the limit of small cosmological constant and vanishing torsion and the teleparallel limit. © 2014 American Physical Society.
Wed, 25 Jun 2014 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/2522014-06-25T00:00:00Z
- Pairing instabilities of Dirac composite fermionshttps://physrep.ff.bg.ac.rs/handle/123456789/23Title: Pairing instabilities of Dirac composite fermions
Authors: Milovanović, M. V.; Dimitrijević-Ćirić, Marija; Juričić, V.
Abstract: Recently, a Dirac (particle-hole symmetric) description of composite fermions in the half-filled Landau level (LL) was proposed [D. T. Son, Phys. Rev. X 5, 031027 (2015)2160-330810.1103/PhysRevX.5.031027], and we study its possible consequences on BCS (Cooper) pairing of composite fermions (CFS). One of the main consequences is the existence of anisotropic states in single-layer and bilayer systems, which was previously suggested in Jeong and Park [J. S. Jeong and K. Park, Phys. Rev. B 91, 195119 (2015)PRBMDO1098-012110.1103/PhysRevB.91.195119]. We argue that in the half-filled LL in the single-layer case the gapped states may sustain anisotropy, because isotropic pairings may coexist with anisotropic ones. Furthermore, anisotropic pairings with the addition of a particle-hole symmetry-breaking mass term may evolve into rotationally symmetric states, i.e., Pfaffian states of Halperin-Lee-Read (HLR) ordinary CFS. On the basis of the Dirac formalism, we argue that in the quantum Hall bilayer at total filling factor 1, with decreasing distance between the layers, weak pairing of p-wave paired CFS is gradually transformed from Dirac to ordinary, HLR-like, with a concomitant decrease in the CF number. Global characterization of low-energy spectra based on the Dirac CFS agrees well with previous calculations performed by exact diagonalization on a torus. Finally, we discuss features of the Dirac formalism when applied in this context.
Thu, 08 Sep 2016 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/232016-09-08T00:00:00Z
- Yang-Mills theory in the S O (2, 3) model of noncommutative gravityhttps://physrep.ff.bg.ac.rs/handle/123456789/71Title: Yang-Mills theory in the S O (2, 3) model of noncommutative gravity
Authors: Dimitrijević-Ćirić, Marija; Gočanin, Dragoljub; Konjik, Nikola; Radovanović, Voja
Abstract: According to the standard cosmological model, thermodynamic conditions of the early Universe were such that nuclear matter existed in the state of quark-gluon plasma, rather than hadrons. On the other hand, it is generally believed that quantum gravity effects become ever more stronger as we approach the Big Bang, in particular, we expect that the phenomenon of space-time noncommutativity will be significant. Thus we are led to consider the properties of quarks and gluons in noncommutative space-time. For this, we employ the SO(2, 3) model of noncommutative gravity. As a first step towards the full theoretical treatment of the effects of noncommutativity on quark-gluon plasma, our main goal in this paper is to consistently incorporate Yang-Mills gauge fields in the SO(2, 3) framework and investigate their coupling to gravity that arises due to space-time noncommutativity. We construct an action that is invariant under deformed SO(2, 3) × SU(N) gauge transformations and expand it perturbatively in orders of the canonical deformation parameter αβ via Seiberg-Witten map. In particular, we analyze the flat-space-time limit and demonstrate that residual noncommutativity induces various new couplings of quarks and gluons.
Mon, 10 Dec 2018 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/712018-12-10T00:00:00Z
- Noncommutative electrodynamics from SO(2 , 3) <inf>⋆</inf> model of noncommutative gravityhttps://physrep.ff.bg.ac.rs/handle/123456789/72Title: Noncommutative electrodynamics from SO(2 , 3) <inf>⋆</inf> model of noncommutative gravity
Authors: Dimitrijević-Ćirić, Marija; Gočanin, Dragoljub; Konjik, Nikola; Radovanović, Voja
Abstract: In our previous work we have constructed a model of noncommutative (NC) gravity based on SO(2 , 3) ⋆ gauge symmetry. In this paper we extend the model by adding matter fields: fermions and a U(1) gauge field. Using the enveloping algebra approach and the Seiberg–Witten map we construct actions for these matter fields and expand the actions up to first order in the noncommutativity (deformation) parameter. Unlike in the case of pure NC gravity, first non-vanishing NC corrections are linear in the noncommutativity parameter. In the flat space–time limit we obtain a non-standard NC Electrodynamics. Finally, we discuss effects of noncommutativity on relativistic Landau levels of an electron in a constant background magnetic field and in addition we calculate the induced NC magnetic dipole moment of the electron.
Sun, 01 Jul 2018 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/722018-07-01T00:00:00Z
- U(1) gauge field theory on κ-Minkowski spacehttps://physrep.ff.bg.ac.rs/handle/123456789/264Title: U(1) gauge field theory on κ-Minkowski space
Authors: Dimitrijević-Ćirić, Marija; Jonke, Larisa; Möller, Lutz
Abstract: This study of U(1) gauge field theory on the kappa-deformed Minkowski spacetime extends previous work on gauge field theories on this type of noncommutative spacetime. We discuss in detail the properties of the Seiberg-Witten map and the resulting effective action for U(1) gauge theory with fermionic matter expanded in ordinary fields. We construct the conserved gauge current, fix part of the ambiguities in the Seiberg-Witten map and obtain an effective U(1) action invariant under the action of the undeformed Poincaré group. © SISSA 2005.
Thu, 01 Sep 2005 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/2642005-09-01T00:00:00Z
- Gauge theories on the κ -Minkowski spacetimehttps://physrep.ff.bg.ac.rs/handle/123456789/266Title: Gauge theories on the κ -Minkowski spacetime
Authors: Dimitrijević-Ćirić, Marija; Meyer, F.; Möller, L.; Wess, J.
Abstract: This study of gauge field theories on κ -deformed Minkowski spacetime extends previous work on field theories on this example of a non-commutative spacetime. We construct deformed gauge theories for arbitrary compact Lie groups using the concept of enveloping algebra-valued gauge transformations and the Seiberg-Witten formalism. Derivative-valued gauge fields lead to field strength tensors as the sum of curvature- and torsion-like terms. We construct the Lagrangians explicitly to first order in the deformation parameter. This is the first example of a gauge theory that possesses a deformed Lorentz covariance. © Springer-Verlag/Societá Italiana di Fisica 2004.
Thu, 01 Jan 2004 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/2662004-01-01T00:00:00Z
- Noncommutative scalar field in the nonextremal Reissner-Nordström background: Quasinormal mode spectrumhttps://physrep.ff.bg.ac.rs/handle/123456789/412Title: Noncommutative scalar field in the nonextremal Reissner-Nordström background: Quasinormal mode spectrum
Authors: Dimitrijević-Ćirić, Marija; Konjik, Nikola; Samsarov, Andjelo
Abstract: In our previous work [M. D. Cirić et al., Classical Quantum Gravity 35, 175005 (2018)CQGRDG0264-938110.1088/1361-6382/aad201] we constructed a model of a noncommutative, charged, and massive scalar field based on the angular twist. Then we used this model to analyze the motion of the scalar field in the Reissner-Nordström black hole background. In particular, we determined the quasinormal mode (QNM) spectrum analytically in the near-extremal limit. To broaden our analysis, in this paper we apply a well-defined numerical method, the continued fraction method, and calculate the QNM spectrum for a nonextremal Reissner-Nordström black hole. To check the validity of our analytic calculations, we compare results of the continued fraction method in the near extremal limit with the analytic results obtained in the previous paper. We find that the results are in good agreement. For completeness, we also study the QNM spectrum in the Wentzel-Kramers-Brillouin approximation.
Mon, 01 Jun 2020 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/4122020-06-01T00:00:00Z
- Dynamical noncommutativity and noether theorem in twisted φ<sup>*4</sup> theoryhttps://physrep.ff.bg.ac.rs/handle/123456789/253Title: Dynamical noncommutativity and noether theorem in twisted φ<sup>*4</sup> theory
Authors: Aschieri, Paolo; Castellani, Leonardo; Dimitrijević-Ćirić, Marija
Abstract: A *-product is defined via a set of commuting vector fields X a = eaμ(x)∂μ, and used in a φ*4 theory coupled to the eaμ(x) fields. The *-product is dynamical, and the vacuum solution φ = 0, eaμ= δa μ reproduces the usual Moyal product. The action is invariant under rigid translations and Lorentz rotations, and the conserved energy-momentum and angular momentum tensors are explicitly derived. © 2008 Springer.
Tue, 01 Jul 2008 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/2532008-07-01T00:00:00Z
- A gravity theory on noncommutative spaceshttps://physrep.ff.bg.ac.rs/handle/123456789/274Title: A gravity theory on noncommutative spaces
Authors: Aschieri, Paolo; Blohmann, Christian; Dimitrijević-Ćirić, Marija; Meyer, Frank; Schupp, Peter; Wess, Julius
Abstract: A deformation of the algebra of diffeomorphisms is constructed for canonically deformed spaces with constant deformation parameter θ. The algebraic relations remain the same, whereas the comultiplication rule (Leibniz rule) is different from the undeformed one. Based on this deformed algebra, a covariant tensor calculus is constructed and all the concepts such as metric, covariant derivatives, curvature and torsion can be defined on the deformed space as well. The construction of these geometric quantities is presented in detail. This leads to an action invariant under the deformed diffeomorphism algebra and can be interpreted as a θ-deformed Einstein-Hilbert action. The metric or the vierbein field will be the dynamical variable as they are in the undeformed theory. The action and all relevant quantities are expanded up to second order in θ. © 2005 IOP Publishing Ltd.
Wed, 07 Sep 2005 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/2742005-09-07T00:00:00Z
- AdS-inspired noncommutative gravity on the Moyal planehttps://physrep.ff.bg.ac.rs/handle/123456789/242Title: AdS-inspired noncommutative gravity on the Moyal plane
Authors: Dimitrijević-Ćirić, Marija; Radovanović, Voja; Atefančić, Hrvoje
Abstract: We consider noncommutative gravity on a space with canonical noncommutativity that is based on the commutative MacDowell-Mansouri action. Gravity is treated as gauge theory of the noncommutative SO(1,3) group, and the Seiberg-Witten map is used to express noncommutative fields in terms of the corresponding commutative fields. In the commutative limit the noncommutative action reduces to the Einstein-Hilbert action plus the cosmological term and the topological Gauss-Bonnet term. After the Seiberg-Witten expansion in the noncommutative parameter the first order correction to the action, as expected, vanishes. We calculate the second order correction and write it in a manifestly gauge covariant way. © 2012 American Physical Society.
Tue, 27 Nov 2012 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/2422012-11-27T00:00:00Z
- L<inf>∞</inf>-algebras of Einstein-Cartan-Palatini gravityhttps://physrep.ff.bg.ac.rs/handle/123456789/905Title: L<inf>∞</inf>-algebras of Einstein-Cartan-Palatini gravity
Authors: Dimitrijević-Ćirić, Marija; Giotopoulos, Grigorios; Radovanović, Voja; Szabo, Richard J.
Abstract: We give a detailed account of the cyclic L∞-algebra formulation of general relativity with a cosmological constant in the Einstein-Cartan-Palatini formalism on spacetimes of arbitrary dimension and signature, which encompasses all symmetries, field equations, and Noether identities of gravity without matter fields. We present a local formulation as well as a global covariant framework, and an explicit isomorphism between the two L∞-algebras in the case of parallelizable spacetimes. By duality, we show that our L∞-algebras describe the complete Batalin-Vilkovisky-Becchi-Rouet-Stora-Tyutin formulation of Einstein-Cartan-Palatini gravity. We give a general description of how to extend on-shell redundant symmetries in topological gauge theories to off-shell correspondences between symmetries in terms of quasi-isomorphisms of L∞-algebras. We use this to extend the on-shell equivalence between gravity and Chern-Simons theory in three dimensions to an explicit L∞-quasi-isomorphism between differential graded Lie algebras, which applies off-shell and for degenerate dynamical metrics. In contrast, we show that there is no morphism between the L∞-algebra underlying gravity and the differential graded Lie algebra governing BF theory in four dimensions.
Sun, 01 Nov 2020 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/9052020-11-01T00:00:00Z
- Noncommutative gravity and the relevance of the θ-constant deformationhttps://physrep.ff.bg.ac.rs/handle/123456789/272Title: Noncommutative gravity and the relevance of the θ-constant deformation
Authors: Dimitrijević-Ćirić, Marija; Nikolić, B.; Radovanović, Voja
Abstract: The breaking of diffeomorphism invariance in the Moyal-Weyl (θ-constant) noncommutative (NC) space-time is a well-known and a long-standing problem. It makes the construction of NC gravity models and interpretation of their results very difficult. In order to solve this problem in this letter we construct a NC gravity action based on the NC SO(2, 3)∗ gauge group and the Seiberg-Witten expansion. The NC equations of motion show that the noncommutativity plays the role of a source for the curvature and/or torsion. Finally, we calculate the NC corrections to the Minkowski space-time and show that in the presence of noncommutativity the Minkowski space-time becomes curved, but remains torsion-free. More importantly, we show that the coordinate system we are using is given by the Fermi normal coordinates; the NC deformation is constant in this particular reference system. The breaking of diffeomorphism invariance is understood as a consequence of working in a preferred reference system. In an arbitrary reference system, the NC deformation is obtained by an appropriate coordinate transformation.
Sat, 01 Apr 2017 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/2722017-04-01T00:00:00Z
- Effective description of Chern insulatorshttps://physrep.ff.bg.ac.rs/handle/123456789/257Title: Effective description of Chern insulators
Authors: Dobardžić, Edib; Dimitrijević-Ćirić, Marija; Milovanović, M. V.
Abstract: The Berry curvature in Chern insulators appears to be a non-gauge-invariant quantity and does not immediately allow local length characterization. However, in two examples of two- and three-band models that we discuss, we find high-symmetry points in the Brillouin zone that have the Berry curvature invariant under diagonal gauge transformations, and may serve as expansion points of geometrical description. On the basis of the geometrical description, in the case of the Dirac based two-band Chern insulators, we conclude that the characteristic length based on the value of the Berry curvature at the expansion point plays the role of the magnetic length in the expression for the Hall viscosity. In the case of two-band models, the characteristic "cyclotron" spin is equal to 1/2, while in the three-band kagome case this spin is likely nonquantized and nonuniversal. © 2014 American Physical Society.
Thu, 19 Jun 2014 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/2572014-06-19T00:00:00Z
- D-deformed Wess-Zumino model and its renormalizability propertieshttps://physrep.ff.bg.ac.rs/handle/123456789/245Title: D-deformed Wess-Zumino model and its renormalizability properties
Authors: Dimitrijević-Ćirić, Marija; Radovanović, Voja
Abstract: Using the methods developed in earlier papers we analyze a new type of deformation of the superspace. The twist we use to deform the N = 1 SUSY Hopf algebra is non-hermitian and is given in terms of the covariant derivatives D α. A SUSY invariant deformation of the Wess-Zumino action is constructed and compared with results already known in the literature. Finally, by calculating divergences of the two-point Green functions a preliminary analysis of renormalizability properties of the constructed model is done. As expected, there is no renormalization of mass and no tadpole diagrams appear. © 2009 SISSA.
Thu, 16 Jul 2009 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/2452009-07-16T00:00:00Z
- Quantum corrections for a Bañados-Teitelboim-Zanelli black hole via the 2D reduced modelhttps://physrep.ff.bg.ac.rs/handle/123456789/210Title: Quantum corrections for a Bañados-Teitelboim-Zanelli black hole via the 2D reduced model
Authors: Burić, Maja; Dimitrijević-Ćirić, Marija; Radovanović, Voja
Abstract: The one-loop quantum corrections for a Bañados-Teitelboim-Zanelli (BTZ) black hole are considered using a dimensionally reduced 2D model. Two cases are analyzed: minimally coupled and conformally coupled 3D scalar matter. In the minimal case, Hartle-Hawking and Unruh vacuum states are defined and the corresponding semiclassical corrections of the geometry are found. The calculations are done for the conformal case too, in order to make a comparison with the exact results obtained previously for a spinless BTZ black hole. The exact corrections for an AdS2 black hole for the 2D minimally coupled scalar field in Hartle-Hawking and Boulware states are found as a subcase. ©2002 The American Physical Society.
Tue, 01 Jan 2002 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/2102002-01-01T00:00:00Z
- Generalized Bloch theorem and topological characterizationhttps://physrep.ff.bg.ac.rs/handle/123456789/255Title: Generalized Bloch theorem and topological characterization
Authors: Dobardžić, Edib; Dimitrijević-Ćirić, Marija; Milovanović, M. V.
Abstract: The Bloch theorem enables reduction of the eigenvalue problem of the single-particle Hamiltonian that commutes with the translational group. Based on a group theory analysis we present a generalization of the Bloch theorem that incorporates all additional symmetries of a crystal. The generalized Bloch theorem constrains the form of the Hamiltonian which becomes manifestly invariant under additional symmetries. In the case of isotropic interactions the generalized Bloch theorem gives a unique Hamiltonian. This Hamiltonian coincides with the Hamiltonian in the periodic gauge. In the case of anisotropic interactions the generalized Bloch theorem allows a family of Hamiltonians. Due to the continuity argument we expect that even in this case the Hamiltonian in the periodic gauge defines observables, such as Berry curvature, in the inverse space. For both cases we present examples and demonstrate that the average of the Berry curvatures of all possible Hamiltonians in the Bloch gauge is the Berry curvature in the periodic gauge.
Mon, 16 Mar 2015 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/2552015-03-16T00:00:00Z
- Nonassociative differential geometry and gravityhttps://physrep.ff.bg.ac.rs/handle/123456789/20Title: Nonassociative differential geometry and gravity
Authors: Dimitrijević-Ćirić, Marija
Abstract: In this short contribution we introduce a nonassocaitive deformation of differential geometry and General Relativity. The nonassociativity is based on the string theory nongeometric R-flux. We use the twist formalism to consistently deform the algebra of infinitesimal diffeomorphisms into the quasi Hopf algebra of (deformed) infnitesimal diffeomorphisms and introduce the NA deformation of differential geometry. In particualr, we define the Levi-Civita connection, curvature tensor and torsion. The space-time quantities (curvature, torsion) are obtained by the zero momenum leaf projection to the space-time. The vacuum Einstein equation in space-time, expanded up to first order in the deformation parameter κ~ is obtained.
Tue, 01 Jan 2019 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/202019-01-01T00:00:00Z
- Noncommutative field theory from an angular twisthttps://physrep.ff.bg.ac.rs/handle/123456789/18Title: Noncommutative field theory from an angular twist
Authors: Dimitrijević-Ćirić, Marija; Konjik, Nikola; Samsarov, Andjelo
Abstract: Black hole (BH) perturbation is followed by a ringdown phase which is dominated by quasinormal modes (QNM). These modes may provide key signature of the gravitational waves. The presence of a deformed spacetime structure may distort this signal. In order to account for such effects, we consider a toy model consisting of a noncommutative charged scalar field propagating in a realistic black hole background. We then analyse the corresponding field dynamics by applying the methods of the Hopf algebra deformation by Drinfeld twist. The latter framework is well suited for incorporating deformed symmetries into a study of this kind. As a result, we obtain the BH QNM spectrum that, besides containing the intrinsic information about a black hole that is being analysed, also carry the information about the underlying structure of spacetime.
Tue, 01 Jan 2019 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/182019-01-01T00:00:00Z
- The noncommutative SO(2, 3)∗ gravity modelhttps://physrep.ff.bg.ac.rs/handle/123456789/21Title: The noncommutative SO(2, 3)∗ gravity model
Authors: Dimitrijevic Ciric, Marija; Gočanin, Dragoljub; Konjik, Nikola; Radovanović, Voja
Abstract: In this review, noncommutative gravity is treated as a gauge theory of the noncommutative SO(2,3)∗ group. We assume that the spacetime deformation is canonical. The Seiberg-Witten map is used to express noncommutative fields in terms of the corresponding commutative fields. In addition to pure gravity, we consider couplings to matter fields, in particular, fermion and U(1) gauge field. The analysis can be extended to non Abelian gauge fields and scalar fields.
Sun, 01 Jan 2017 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/212017-01-01T00:00:00Z
- Deformed gauge theorieshttps://physrep.ff.bg.ac.rs/handle/123456789/273Title: Deformed gauge theories
Authors: Dimitrijević-Ćirić, Marija
Abstract: In this lecture we discuss two possible ways of introducing gauge theories on non-commutative spaces. In the first approach the algebra of gauge transformations is unchanged, but the Leibniz rule changes (compared with gauge theories on commutative space). Consistency of equations of motion forces gauge field to be enveloping algebra-valued, which leads to new degrees of freedom. In the second approach we have to go to the enveloping algebra again if we want noncommu-tative gauge transformations to close in the algebra. However, no new degrees of freedom appear here because of the Seiberg-Witten map. This map enables one to express noncommutative gauge parameter and fields in terms of the corresponding commutative variables.
Fri, 01 Dec 2006 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/2732006-12-01T00:00:00Z
- Field theory on nonanticommutative superspacehttps://physrep.ff.bg.ac.rs/handle/123456789/241Title: Field theory on nonanticommutative superspace
Authors: Dimitrijević-Ćirić, Marija; Radovanović, Voja; Wess, Julius
Abstract: We discuss a deformation of the Hopf algebra of supersymmetry (SUSY) transformations based on a special choice of a twist. As usual, algebra itself remains unchanged, but the comultiplication changes. This leads to a deformed Leibniz rule for SUSY transformations. Superfields are multiplied by using a *-product which is noncommutative, hermitian and finite when expanded in power series of the deformation parameter. One possible deformation of the Wess-Zumino action is proposed and analysed in detail. Differently from most of the literature concerning this subject, we work in Minkowski space-time. © 2008 Wiley-VCH Verlag GmbH & Co. KGaA.
Tue, 01 Apr 2008 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/2412008-04-01T00:00:00Z
- Noncommutative gravity and the Seiberg-Witten maphttps://physrep.ff.bg.ac.rs/handle/123456789/251Title: Noncommutative gravity and the Seiberg-Witten map
Authors: Dimitrijević-Ćirić, Marija; Radovanović, Voja; Simonović, Ilija
Abstract: We discus the Seiberg-Witten map and its application to noncommutative gauge theories. In particular, we present the method of composite fields which we find very useful when calculating higher order corrections in noncommutative gauge theories. Two examples are given: one is the calculation of the second order correction for the noncommutative Yang-Mills action and the other is the calculation of the corrections for the AdS inspired noncommutative gravity action. The second example we discuss in more details.
Sun, 01 Jan 2012 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/2512012-01-01T00:00:00Z
- Deformed symmetries in noncommutative field theorieshttps://physrep.ff.bg.ac.rs/handle/123456789/261Title: Deformed symmetries in noncommutative field theories
Authors: Dimitrijević-Ćirić, Marija
Abstract: In this lecture we discuss the problem of symmetries in noncommutative field theories. The twist approach is used to derive deformed symmetries. In this approach the algebra of symmetry generators remains undeformed, but the Leibniz rules for the generators change. We give some examples. In the case of the canonically deformed space the twisted Poincare symmetry is analyzed and the problem of nonconserved charges is discussed. A way to overcome this problem is to introduce a dynamical noncommutativity and we briefly describe it.
Mon, 01 Dec 2008 00:00:00 GMThttps://physrep.ff.bg.ac.rs/handle/123456789/2612008-12-01T00:00:00Z