Zobrazeno 1 - 10
of 39
pro vyhledávání: '"Damianos Iosifidis"'
Autor:
Damianos Iosifidis, Friedrich W. Hehl
Publikováno v:
Physics Letters B, Vol 850, Iss , Pp 138498- (2024)
We derive the equations of motion of a test particle with intrinsic hypermomentum in spacetimes with both torsion S and nonmetricity Q (along with curvature R). Accordingly, S and Q can be measured by tracing out the trajectory followed by a hypermom
Externí odkaz:
https://doaj.org/article/f817fbf81b574bf0a4cb722bcfed94f4
Publikováno v:
European Physical Journal C: Particles and Fields, Vol 83, Iss 3, Pp 1-14 (2023)
Abstract We study the potential effects of spacetime non-metricity in cosmology. In the spirit of Einstein–Cartan gravity, but with non-metricity replacing torsion, we consider the Einstein–Hilbert action and assume zero torsion. Adopting certain
Externí odkaz:
https://doaj.org/article/fd26e1790331449086b5935de00c8482
Autor:
Damianos Iosifidis
Publikováno v:
European Physical Journal C: Particles and Fields, Vol 82, Iss 7, Pp 1-14 (2022)
Abstract We consider the most general 11 parameter parity even quadratic Metric-Affine Theory whose action consists of the usual Einstein–Hilbert plus the 11 quadratic terms in torsion, non-metricity as well as their mixing. By following a certain
Externí odkaz:
https://doaj.org/article/816797d159ca4d28b49666d847c86523
Autor:
Damianos Iosifidis, Lucrezia Ravera
Publikováno v:
European Physical Journal C: Particles and Fields, Vol 81, Iss 8, Pp 1-13 (2021)
Abstract We study the cosmology of a quadratic metric-compatible torsionful gravity theory in the presence of a perfect hyperfluid. The gravitational action is an extension of the Einstein–Cartan theory given by the usual Einstein–Hilbert contrib
Externí odkaz:
https://doaj.org/article/74ae31d0b68340e68d7d170c9338eaa2
Autor:
Damianos Iosifidis
Publikováno v:
European Physical Journal C: Particles and Fields, Vol 80, Iss 11, Pp 1-20 (2020)
Abstract We develop a novel model for cosmological hyperfluids, that is fluids with intrinsic hypermomentum that induce spacetime torsion and non-metricity. Imposing the cosmological principle to metric-affine spaces, we present the most general cova
Externí odkaz:
https://doaj.org/article/d8faa128e43340b4bd3689a008b1adc9
Publikováno v:
European Physical Journal C: Particles and Fields, Vol 79, Iss 4, Pp 1-12 (2019)
Abstract We consider spatially homogeneous and isotropic cosmologies with non-vanishing torsion, which assumes a specific form due to the high symmetry of these universes. Using covariant and metric-based techniques, we derive the torsional versions
Externí odkaz:
https://doaj.org/article/c908afef5a5d4e9290df17e7a00438e1
Autor:
Damianos Iosifidis
Publikováno v:
Universe, Vol 8, Iss 6, p 312 (2022)
In this paper, focusing on 4-dimensional space, we extend our previous results of solving linear tensor equations. In particular, we consider a 30-parameter linear tensor equation for the unknown tensor component Nαμν in terms of the known compone
Externí odkaz:
https://doaj.org/article/af86c9e9426c440aa8281f9ff9a89323
Autor:
Jose Beltrán Jiménez, Lavinia Heisenberg, Damianos Iosifidis, Alejandro Jiménez-Cano, Tomi S. Koivisto
Publikováno v:
Physics Letters B, Vol 805, Iss , Pp - (2020)
In this Letter we consider a general quadratic parity-preserving theory for a general flat connection. Imposing a local symmetry under the general linear group singles out the general teleparallel equivalent of General Relativity carrying both torsio
Externí odkaz:
https://doaj.org/article/29a581b6229d4ffcaede55c9ebb7c478
Autor:
Damianos Iosifidis
Publikováno v:
Universe, Vol 7, Iss 10, p 383 (2021)
We develop a systematic way to solve linear equations involving tensors of arbitrary rank. We start off with the case of a rank 3 tensor, which appears in many applications, and after finding the condition for a unique solution we derive this solutio
Externí odkaz:
https://doaj.org/article/692f35a55b6f44acab5654dcb897c4a9
Publikováno v:
Universe, Vol 7, Iss 8, p 262 (2021)
We derive the full set of field equations for the metric-affine version of the Myrzakulov gravity model and also extend this family of theories to a broader one. More specifically, we consider theories whose gravitational Lagrangian is given by F(R,T
Externí odkaz:
https://doaj.org/article/eeaf25bf361640589ec11d9a0bb22dd2