Zobrazeno 1 - 10
of 52
pro vyhledávání: '"Zacharias Roupas"'
Autor:
Zacharias Roupas
Publikováno v:
European Physical Journal C: Particles and Fields, Vol 82, Iss 3, Pp 1-14 (2022)
Abstract While spacetime in the vicinity outside astrophysical black holes is believed to be well understood, the event horizon and the interior remain elusive. Here, we discover a degenerate infinite spectrum of novel general relativity solutions wi
Externí odkaz:
https://doaj.org/article/2ef118ae63264f598c549cd21c781926
Autor:
Zacharias Roupas, Gamal G. L. Nashed
Publikováno v:
European Physical Journal C: Particles and Fields, Vol 80, Iss 10, Pp 1-11 (2020)
Abstract Dense nuclear matter is expected to be anisotropic due to effects such as solidification, superfluidity, strong magnetic fields, hyperons, pion-condensation. Therefore an anisotropic neutron star core seems more realistic than an ideally iso
Externí odkaz:
https://doaj.org/article/86a19ea267ed4e12b897b01faf7fe1e7
Autor:
Zacharias Roupas
Publikováno v:
Symmetry, Vol 11, Iss 12, p 1435 (2019)
Thermal energy points towards a disordered, completely uniform state act to counter gravity’s tendency to generate order and structure through gravitational collapse. It is, therefore, expected to contribute to the stabilization of a self-gravitati
Externí odkaz:
https://doaj.org/article/4dcdc0b52ab64830a522152b3f6ea285
Autor:
Zacharias Roupas
Publikováno v:
Universe, Vol 5, Iss 1, p 12 (2019)
The gravitational instability, responsible for the formation of the structure of the Universe, occurs below energy thresholds and above spatial scales of a self-gravitating expanding region, when thermal energy can no longer counterbalance self-gravi
Externí odkaz:
https://doaj.org/article/6bdb131dca57447d84cfd668fae93f25
Autor:
Zacharias Roupas
Publikováno v:
Physics of the Dark Universe. 40:101181
We derive the dark energy fluid equation of state $P = -\epsilon = {\rm const.}$ as an extremum of entropy, subject to the Hamiltonian constraint of General Relativity. However, we identify perturbations that can render this extremum an entropy minim
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ca1698c635e96fba4b74c5c4eaae31c1
https://doi.org/10.1016/j.dark.2023.101181
https://doi.org/10.1016/j.dark.2023.101181
Publikováno v:
Monthly Notices of the Royal Astronomical Society
Monthly Notices of the Royal Astronomical Society, Oxford University Press (OUP): Policy P-Oxford Open Option A, 2020, 499 (2), pp.2575-2586. ⟨10.1093/mnras/staa2972⟩
Monthly Notices of the Royal Astronomical Society, Oxford University Press (OUP): Policy P-Oxford Open Option A, 2020, 499 (2), pp.2575-2586. ⟨10.1093/mnras/staa2972⟩
Fuzzy dark matter (FDM) consisting of ultra-light axions has been invoked to alleviate galactic-scale problems in the cold dark matter scenario. FDM fluctuations, created via the superposition of waves, can impact the motion of a central supermassive
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::fcbd2559495f5430c5530fe743e76d69
https://doi.org/10.1093/mnras/staa2972
https://doi.org/10.1093/mnras/staa2972
At sufficiently high densities and low temperatures matter is expected to behave as a degenerate Fermi gas of quarks forming Cooper pairs, namely a color superconductor, as was originally suggested by Alford, Rajagopal, and Wilczek [Nucl. Phys. B537,
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::98af036a19c9d7c105361302ca0d9d68
http://arxiv.org/abs/2010.11020
http://arxiv.org/abs/2010.11020
Autor:
Gamal G. L. Nashed, Zacharias Roupas
Publikováno v:
European Physical Journal
European Physical Journal C: Particles and Fields, Vol 80, Iss 10, Pp 1-11 (2020)
European Physical Journal C: Particles and Fields, Vol 80, Iss 10, Pp 1-11 (2020)
Dense nuclear matter is expected to be anisotropic due to effects such as solidification, superfluidity, strong magnetic fields, hyperons, pion-condesation. Therefore an anisotropic neutron star core seems more realistic than an ideally isotropic one
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::d3f57b82510e5d7b3757ac1601b0a612
http://repo.scoap3.org/api
http://repo.scoap3.org/api
Autor:
Zacharias Roupas
Recent theoretical and numerical developments supported by observational evidence strongly suggest that many globular clusters host a black hole (BH) population in their centers. This stands in contrast to the prior long-standing belief that a BH sub
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::44fb793d98d9c365a5053842d8c54aca
http://arxiv.org/abs/2006.12755
http://arxiv.org/abs/2006.12755
Autor:
Zacharias Roupas
Publikováno v:
Journal of Statistical Mechanics: Theory and Experiment. 2021:093207
The problem of time is a notable obstacle towards the recognition of quantum theory as the ultimate fundamental description of nature. Quantum theory may not be complete if founded upon classical notions. Louis de Broglie, seeming to be more or less
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ab57a6643023f8c19d2247e4ce072374
https://doi.org/10.1088/1742-5468/ac21d5
https://doi.org/10.1088/1742-5468/ac21d5