105 citations · 707 across the 36 of their papers we have counts for
15 papers · 1 filter
Thermodynamic instability of dark energy equation of state
Zacharias Roupas
We derive the dark energy fluid equation of state as an extremum of entropy, subject to the Hamiltonian constraint of General Relativity. However, we identif…
The Cosmological Black Hole
Zacharias Roupas
We briefly review the recent novel solution of General Relativity, we call the cosmological black hole, firstly discovered in [Roupas, Z. Eur. Phys. J. C 82, 255 (2022)]. A dark en…
Detectable universes inside regular black holes
Zacharias Roupas
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 degenera…
Relativistic Gravitational Collapse by Thermal Mass
Zacharias Roupas
Gravity and thermal energy are universal phenomena which compete over the stabilization of astrophysical systems. The former induces an inward pressure driving collapse and the lat…
Secondary component of gravitational-wave signal GW190814 as an anisotropic neutron star
Zacharias Roupas
The gravitational-wave signal GW190814 involves a compact object with mass within the so-called low mass gap. As yet, a general consensus on its nature,…
Anisotropic Neutron Stars Modelling: Constraints in Krori-Barua Spacetime
Zacharias Roupas, Gamal G. L. Nashed
Dense nuclear matter is expected to be anisotropic due to effects such as solidification, superfluidity, strong magnetic fields, hyperons, pion-condesation. Therefore an anisotropi…