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Remigiusz Durka

Publications and source records attributed to Remigiusz Durka.

11 recordsLinked to original sources

Charges of supergravity

We study conserved charges of $\mathcal{N}=1$ supergravity formulated as a constrained BF theory based on the $\OSp(1|4)$ superalgebra. Using the covariant phase space formalism, we derive bulk and boundary contributions to the symplectic structure and construct charges associated with Lorentz transformations, supersymmetry, translations, and diffeomorphisms. We show that the algebra of boundary charges reproduces the expected superalgebra, while translational charges vanish on-shell due to the super-torsion constraint, leaving Lorentz and supersymmetry as the non-trivial generators.

hep-th

Resonant enlargements of the Poincare/AdS (super)algebras from pattern-based analysis

Applying an efficient pattern-based computational method of generating the so-called 'resonating' algebraic structures results in a broad class of the new Lie (super)algebras. Those structures inherit the AdS base (anti)commutation pattern and can be treated as the enlargements of the Poincaré or Anti-de-Sitter (super)algebras. Obtained superalgebras are rooted in the semigroup expansion method and Maxwell and Soroka-Soroka algebras, spanned by the Lorentz generator $J_{ab}$, translations $P_{a}$ and additional Lorentz-like generator $Z_{ab}$. Considered configurations include cases up to two fermionic supercharges $Q_α$ and offer interesting modifications to the gauge (super)gravity theories.

hep-th

A tale of two theories of gravity in asymptotically Anti-de Sitter spacetime

We consider two BF formulations of the theory of gravity with a negative cosmological constant, of Plebanski and of MacDowell-Mansouri. Both give the standard Einstein equations in the bulk but differ in expressions of edge charges. We compute the asymptotic charges explicitly in both theories for AdS-Schwarzschild, AdS-Kerr, and AdS-Taub--NUT solutions. We find that while in the case of the Plebanski theory the charges are divergent, they are finite for MacDowell-Mansouri theory. Furthermore, we show that in the case of the arbitrary asymptotically AdS spacetimes, MacDowell--Mansouri asymptotic charges, action, and symplectic form are all finite. Therefore MacDowell-Mansouri theory of gravity in asymptotically AdS spaces does not need any counterterms.

gr-qc

$\mathcal{N}=2$ resonant superalgebra for supergravity

We present new superalgebra for $\mathcal{N}=2$ $D=3,4$ supergravity theory endowed with the $U(1)$ generator. The superalgebra is rooted in the so-called Soroka-Soroka algebra and spanned by the Lorentz $J_{ab}$ and Lorentz-like $Z_{ab}$, translation $P_a$ and $T$ generators, as well as two supercharges $Q^I_α$. It is the only possible realization for a given generator content. We construct a corresponding 3D Chern-Simons supergravity realization of the superalgebra and discuss its relevance.

hep-th

Resonant superalgebras for supergravity

Considering supergravity theory is a natural step in the development of gravity models. This paper follows the ``algebraic`` path and constructs possible extensions of the Poincaré and Anti-de-Sitter algebras, which inherit their basic commutation structure. Previously achieved results of this type are fragmentary and show only a limited fraction of possible algebraic realizations. Our paper presents the newly obtained symmetry algebras, evaluated within an efficient pattern-based computational method of generating the so-called 'resonating' algebraic structures. These supersymmetric extensions of algebras, going beyond the Poincaré and Anti-de Sitter ones, contain additional bosonic generators $Z_{ab}$ (Lorentz-like), and $U_a$ (translational-like) added to the standard Lorentz generator $J_{ab}$ and translation generator $P_{a}$. Our analysis includes all cases up to two fermionic supercharges, $Q_α$ and $Y_α$. The delivered plethora of superalgebras includes few past results and offers a vastness of new examples. The list of the cases is complete and contains all superalgebras up to two of Lorentz-like, translation-like, and supercharge-like generators $(JP+Q)+(ZU+Y)=JPZU+QY$. In the latter class, among $667$ founded superalgebras, the $264$ are suitable for direct supergravity construction. For each of them, one can construct a unique supergravity model defined by the Lagrangian. As an example, we consider one of the algebra configurations and provide its Lagrangian realization.

hep-th

On the number of possible resonant algebras

We explore the question concerning the number of distinct resonant algebras depending on the generator content, which consists of the Lorentz generator, translation, and new additional Lorentz-like and translation-like generators. Such algebra enlargements originate directly from the so-called Maxwell algebra and implementation of the S-expansion framework. Resonant algebras, being a sub-class of the S-expanded algebras, similarly should find use in the construction of gravity and supergravity models and in some other applications. The undertaken task of establishing all the possible resonant algebras is closely related to the subject of finding commutative monoids (semigroups with the identity element) of the particular order, were we additionally enforce the parity condition.

hep-th

Resonant superalgebras and $\mathcal{N}=1$ supergravity theories in three spacetime dimensions

We explore $\mathcal{N}=1$ supersymmetric extensions of algebras going beyond the Poincaré and AdS ones in three spacetime dimensions. Besides reproducing two known examples, we present new superalgebras, which all correspond to supersymmetric extensions with one fermionic charge $Q_α$ concerning the so-called resonant algebras being characterized by the presence of an additional bosonic generator $Z_{a}$, besides the Lorentz $J_{a}$ and translation $P_{a}$ generators. Obtained eight supersymmetric $JPZ+Q$ schemes result directly from obeying super-Jacobi identities. We point out particular requirements that superalgebras have to satisfy to be successfully incorporated within valid supergravity actions. The presented algebraic and Lagrangian framework organizes and helps us better understand relations between the various supergravity and supersymmetric Chern-Simons actions invariant under diverse resonant superalgebras.

hep-th

The first law of black hole thermodynamics for Taub-NUT spacetime

This article focuses on the new approach to the nature of a nut parameter $n$, usually treated as a dual charge to the mass. Instead of thinking about it as a gravitational analog of the magnetic monopole, we will show that the Taub-NUT spacetime conceals a peculiar rotation coming from the Misner strings depending on the nut value. Besides reconciling a number of confusing results present in the literature, this allows us to establish a consistent description of the black hole thermodynamics for the Lorentzian Taub--NUT spacetime with essential contribution from the Misner strings to the angular momentum and total entropy.

gr-qc

Resonant algebras in Chern-Simons model of topological insulators

This paper explores the possibility of using Maxwell algebra and its generalizations called resonant algebras for the unified description of topological insulators. We offer the natural action construction, which includes the relativistic Wen-Zee and other terms, with adjustable coupling constants. By gauging all available resonant algebras formed by Lorentz, translational and Maxwell generators $\{J_a, P_a, Z_a\}$ we present six Chern-Simons Lagrangians with various terms content accounting for different aspects of the topological insulators. Additionally, we provide complementary actions for another invariant metric form, which might turn out useful in some generalized (2+1) gravity models.

hep-th

Dynamical structure of Pure Lovelock gravity

We study dynamical structure of Pure Lovelock gravity in spacetime dimensions higher than four using the Hamiltonian formalism. The action consists of cosmological constant and a single higher-order polynomial in the Riemann tensor. Similarly to Einstein-Hilbert action, it possesses a unique constant curvature vacuum and charged black hole solutions. We analyze physical degrees of freedom and local symmetries in this theory. In contrast to the Einstein-Hilbert case, a number of degrees of freedom depends on the background and can vary from zero to the maximal value carried by the Lovelock theory.

hep-th

Deformed BF theory as a theory of gravity and supergravity

Thesis provides an analysis of various aspects theory of gravity seen as a deformation of a topological SO(2,3) BF theory. Considered framework, originating from the 70's and known as MacDowell-Mansouri gravity, assures the most general form of action, containing the Einstein-Cartan action with a negative cosmological constant, the Holst term, and the topological Euler, Pontryagin and Nieh-Yan invariants. Main goal was to investigate the presence of Barbero-Immirzi parameter in the context of supergravity, as well as black hole thermodynamics arising from the gravitational Noether charges.

gr-qc