Related papers: QCD against black holes?
In order to actually see the hadron-quark transition happening in a neutron star, we point out and study two static conditions (the transition hadronic density must be lower than the neutron star maximum hadronic density; the neutron star…
We solve dynamical equations of motion to determine the conditions under which an over-dense region in the early universe will lead to collapse to a black hole, starting from horizon crossing of the over-dense region to the point of…
Black holes are an apparently unavoidable prediction of classical General Relativity, at least if matter obeys the strong energy condition rho + 3p > 0. However quantum vacuum fluctuations generally violate this condition, as does the eq.…
We consider the evolution of cosmological perturbations at the QCD transition, in particular the sudden reheating from a supercooled universe to the transition temperature. Sudden reheating happens at a specific temperature, hence density,…
A viable model for the dense matter equation of state above the nuclear saturation density includes a hadron-to-quark phase transition at densities relevant to compact objects. In this case, stable hybrid hadron-quark stars can arise. An…
Supermassive black holes are now realized to exist in the centers of most galaxies. The recent discoveries of luminous quasars at redshifts higher than 6 require that these black holes were assembled already when the Universe was less than…
We discuss the possibility for a cooled down and otherwise stable solitary neutron star to make a spontaneous transition to its potential black hole ground state. This fundamental process would mimic a precursorless explosion in which the…
Massive stars (M> 10Msun) end their lives with spectacular explosions due to gravitational collapse. The collapse turns the stars into compact objects such as neutron stars and black holes with the ejection of cosmic rays and heavy…
Black holes (BHs) play a central role in physics. However, gathering observational evidence for their existence is a notoriously difficult task. Current strategies to quantify the evidence for BHs all boil down to looking for signs of…
The nature of core-collapse supernova (SN) explosions is yet incompletely understood. The present article revisits the scenario in which the release of latent heat due to a first-order phase transition, from normal nuclear matter to the…
Phase transitions can play an important role in the cosmological constant problem, allowing the underlying vacuum energy, and therefore the value of the cosmological constant, to change. Deep within the core of neutron stars, the local…
In nucleus-nucleus collisions at ultra-relativistic energies matter is formed with initial energy density significantly exceeding the critical energy density for the transition from hadronic to partonic matter. We will review the…
In stellar core-collapse events matter is heated and compressed to densities above nuclear matter saturation density. For progenitors stars with masses above about 25 solar masses, which eventually form a black hole, the temperatures and…
We investigate observable signatures of a first-order quantum chromodynamics (QCD) phase transition in the context of core collapse supernovae. To this end, we conduct axially symmetric numerical relativity simulations with multi-energy…
We study the backreaction of quantum fields induced through the vacuum polarization and the conformal anomaly on the collapse of a thin shell of dust. It is shown that the final fate of the collapse process depends on the physical…
The evolution of nonlinear density fluctuations around the Jeans mass shortly after cosmological recombination is analyzed using a 3D hydrodynamics/dark--matter code. The Cosmic Background Radiation (CBR) exerts Compton friction on free…
Normal baryonic matter inside an evolved massive star can be intensely compressed by gravity after a supernova. General relativity predicts formation of a black hole if the core material is compressed into a singularity, but the real state…
We investigate the properties of the event horizon in the merger between a large black hole and a smaller neutron star. We find that, if the star is compact enough, then, in its rest frame a horizon begins to grow inside the star before it…
The gravitational collapse of a spherically symmetric star, made of a dust fluid, $\rho_{DM}$, in a background of dark energy, $p = w\rho,\; (w < -1/3)$, is studied. It is found that when only dark energy is present, black holes are {\em…
Within general relativity, black holes are widely regarded as the ultimate benchmark for compactness in the Universe. Recently, however, neutron star models have been constructed in a higher-curvature theory -- quasi-topological gravity…