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B. Cvetkovic

Publications and source records attributed to B. Cvetkovic.

9 recordsLinked to original sources
arXiv2013

3D gravity with propagating torsion: Hamiltonian structure of the scalar sector

We study the Hamiltonian structure of the general parity-invariant model of three-dimensional gravity with propagating torsion, with eight parameters in the Lagrangian. In the scalar sector, containing scalar or pseudoscalar modes with respect to maximally symmetric background, the phenomenon of constraint bifurcation is observed and analyzed. The stability of the Hamiltonian structure under linearization is used to identify dynamically acceptable values of parameters.

gr-qc↗
arXiv2011

Holograms of Conformal Chern-Simons Gravity

We show that conformal Chern-Simons gravity in three dimensions has various holographic descriptions. They depend on the boundary conditions on the conformal equivalence class and the Weyl factor, even when the former is restricted to asymptotic Anti-deSitter behavior. For constant or fixed Weyl factor our results agree with a suitable scaling limit of topologically massive gravity results. For varying Weyl factor we find an enhancement of the asymptotic symmetry group, the details of which depend on certain choices. We focus on a particular example where an affine u(1) algebra related to holomorphic Weyl rescalings shifts one of the central charges by 1. The Weyl factor then behaves as a free chiral boson in the dual conformal field theory.

hep-th↗
arXiv2007

Supersymmetric 3D gravity with torsion: asymptotic symmetries

We study the structure of asymptotic symmetries in N=1+1 supersymmetric extension of three-dimensional gravity with torsion. Using a natural generalization of the bosonic anti-de Sitter asymptotic conditions, we show that the asymptotic Poisson bracket algebra of the canonical generators has the form of two independent super-Virasoro algebras with different central charges.

gr-qc↗
arXiv2006

Covariant description of the black hole entropy in 3D gravity

We study the entropy of the black hole with torsion using the covariant form of the partition function. The regularization of infinities appearing in the semiclassical calculation is shown to be consistent with the grand canonical boundary conditions. The correct value for the black hole entropy is obtained provided the black hole manifold has two boundaries, one at infinity and one at the horizon. However, one can construct special coordinate systems, in which the entropy is effectively associated with only one of these boundaries.

gr-qc↗
arXiv2006

Black hole entropy in 3D gravity with torsion

The role of torsion in quantum three-dimensional gravity is investigated by studying the partition function of the Euclidean theory in Riemann-Cartan spacetime. The entropy of the black hole with torsion is found to differ from the standard Bekenstein-Hawking result, but its form is in complete agreement with the first law of black hole thermodynamics.

gr-qc↗
arXiv2005

Proceedings to the 8th Workshop 'What Comes Beyond the Standard Models', Bled, July 19. - 29., 2005, Slovenia

Contents: 1. Can MPP Together with Weinberg-Salam Higgs Provide Cosmological Inflation? (D.L. Bennett and H.B. Nielsen) 2. Conserved Charges in 3d Gravity With Torsion (M. Blagojevic and B. Cvetkovic) 3. Mass Matrices of Quarks and Leptons in the Approach Unifying Spins and Charges (A. Borstnik Bracic and N.S. Mankoc Borstnik) 4. Dark Matter From Encapsulated Atoms (C.D. Froggatt and H.B. Nielsen) 5. Dirac Sea for Bosons Also and SUSY for Single Particles (Y. Habara, H.B. Nielsen and M. Ninomiya) 6. Searching for Boundary Conditions in Kaluza-Klein-like Theories (D. Lukman, N.S. Mankoc Borstnik and H. B. Nielsen) 7. Second Quantization of Spinors and Clifford Algebra Objects (N.S. Mankoc Borstnik and H. B. Nielsen) 8. Are there Interesting Problems That Could Increase Understanding of Physics and Mathematics? (R. Mirman) 9. Noncommutative Nonsingular Black Holes (P. Nicolini) 10. Compactified Time and Likely Entropy -- World Inside Time Machine: Closed Time-like Curve (H.B. Nielsen and M. Ninomiya) + Astri Kleppe's Song.

hep-ph↗
arXiv2005

Asymptotic charges in 3d gravity with torsion

We discuss some new developments in three-dimensional gravity with torsion, based on Riemann-Cartan geometry. Using the canonical approach, we study the structure of asymptotic symmetry, clarify its fundamental role in defining the gravitational conserved charges, and explore the influence of the asymptotic structure on the black hole entropy.

gr-qc↗
arXiv2004

Canonical structure of 3D gravity with torsion

We study the canonical structure of the topological 3D gravity with torsion, assuming the anti-de Sitter asymptotic conditions. It is shown that the Poisson bracket algebra of the canonical generators has the form of two independent Virasoro algebras with classical central charges. In contrast to the case of general relativity with a cosmological constant, the values of the central charges are different from each other.

gr-qc↗