Zobrazeno 1 - 10
of 145
pro vyhledávání: '"Andrzej Borowiec"'
Autor:
Andrzej Borowiec, Marcin Postolak
Publikováno v:
Physics Letters B, Vol 860, Iss , Pp 139176- (2025)
We found general solutions of matter stress-energy (non-)conservation in scalar-tensor FLRW-type cosmological models by extending the logotropic formalism to the case of non-minimal coupling between the scalar field and new dark fluid candidates. The
Externí odkaz:
https://doaj.org/article/3ba319893c394080a8d3eb538a30788d
Publikováno v:
Journal of High Energy Physics, Vol 2021, Iss 11, Pp 1-38 (2021)
Abstract In this paper we study quantum group deformations of the infinite dimensional symmetry algebra of asymptotically AdS spacetimes in three dimensions. Building on previous results in the finite dimensional subalgebras we classify all possible
Externí odkaz:
https://doaj.org/article/476b47e777e043f58116ce50caaa4b7b
Publikováno v:
Journal of High Energy Physics, Vol 2021, Iss 2, Pp 1-31 (2021)
Abstract BMS symmetry is a symmetry of asymptotically flat spacetimes in vicinity of the null boundary of spacetime and it is expected to play a fundamental role in physics. It is interesting therefore to investigate the structures and properties of
Externí odkaz:
https://doaj.org/article/18263c23087549429e008e3c37d0b6b5
Autor:
Aleksander Kozak, Andrzej Borowiec
Publikováno v:
European Physical Journal C: Particles and Fields, Vol 79, Iss 4, Pp 1-18 (2019)
Abstract A new systematic approach extending the notion of frames to the Palatini scalar–tensor theories of gravity in various dimensions $$n>2$$ n>2 is proposed. We impose frame transformation induced by the group action which includes almost-geod
Externí odkaz:
https://doaj.org/article/692997a4a39341fbb592c5a9c2cb8c45
Publikováno v:
Physics Letters B, Vol 790, Iss , Pp 415-420 (2019)
We present the quantum κ-deformation of BMS symmetry, by generalizing the lightlike κ-Poincaré Hopf algebra. On the technical level our analysis relies on the fact that the lightlike κ-deformation of Poincaré algebra is given by a twist and the
Externí odkaz:
https://doaj.org/article/af28bd0954e04d09964a79ed8818482d
Publikováno v:
European Physical Journal C: Particles and Fields, Vol 78, Iss 4, Pp 1-7 (2018)
Abstract We propose a new formula to explain circular velocity profiles of spiral galaxies obtained from the Starobinsky model in the Palatini formalism. It is based on the assumption that the gravity can be described by two conformally related metri
Externí odkaz:
https://doaj.org/article/a6d19ed2ce4442b2b36d0ba813a2c36a
Publikováno v:
Journal of High Energy Physics, Vol 2017, Iss 10, Pp 1-27 (2017)
Abstract We revisit the notion of quantum Lie algebra of symmetries of a noncommutative spacetime, its elements are shown to be the generators of infinitesimal transformations and are naturally identified with physical observables. Wave equations on
Externí odkaz:
https://doaj.org/article/d356ff4d06a14e228c70f0806b2e7f9f
Publikováno v:
European Physical Journal C: Particles and Fields, Vol 77, Iss 9, Pp 1-9 (2017)
Abstract We consider FRW cosmology in $$f(R)= R+ \gamma R^2+\delta R^3$$ f ( R ) = R + γ R 2 + δ R 3 modified framework. The Palatini approach reduces its dynamics to the simple generalization of Friedmann equation. Thus we study the dynamics in tw
Externí odkaz:
https://doaj.org/article/86b9ba732cbc429b8ea52deecbe5cfc0
Publikováno v:
Physics Letters B, Vol 770, Iss C, Pp 426-430 (2017)
In our previous paper [1] we obtained a full classification of nonequivalent quasitriangular quantum deformations for the complex D=4 Euclidean Lie symmetry o(4;C). The result was presented in the form of a list consisting of three three-parameter, o
Externí odkaz:
https://doaj.org/article/d42b562c6c584c2985a82778e86f9b92
Publikováno v:
European Physical Journal C: Particles and Fields, Vol 77, Iss 6, Pp 1-17 (2017)
Abstract We classify singularities in FRW cosmologies, which dynamics can be reduced to the dynamical system of the Newtonian type. This classification is performed in terms of the geometry of a potential function if it has poles. At the sewn singula
Externí odkaz:
https://doaj.org/article/e8d73a0ed77a4fbeac6d1d6ce19a6b01