Related papers: Chirality in the Early Universe
A chaotic model of the early universe within the framework of the singularity-free solutions of Einstein's equation is suggested. The evolution of our universe at its early stage, starting out as a small domain of the parent universe, is…
Brown dwarfs and giant gas planets are substellar objects whose spectral appearance is determined by the chemical composition of the gas and the solids/liquids in the atmosphere. Atmospheres of substellar objects possess two major scale…
Early JWST observations have revealed the ubiquitous presence in the early Universe, up to z about 16, of extreme baryon concentrations, namely forming globular clusters, extremely dense galaxies that may or may not be UV bright, and…
Chemistry plays a particular role in astrophysics. After atomic hydrogen, helium and their ions, the Universe probably contains more mass in molecules than in any other species. Molecule formation in the early, pre-galactic Universe may…
Observations indicate that the universe is effectively flat, but they do not rule out a closed universe. The role of positive curvature is negligible at late times, but can be crucial in the early universe. In particular, positive curvature…
The abundance and size distribution of quark nuggets (QN), formed a few microseconds after the big bang due to first order QCD phase transition in the early universe, has been estimated. It appears that stable QNs could be a viable…
A possibility of existence of ultra-heavy (quasi)stable particles, mechanisms leading to their large life-time, their production in the early universe, and cosmological manifestations are reviewed.
We formulate the basic postulate of pre-big bang cosmology as one of ``asymptotic past triviality'', by which we mean that the initial state is a generic perturbative solution of the tree-level low-energy effective action. Such a…
According to the standard lore, a prolonged inflation leaves a quantum field theory in a cold, low entropy state. Thus, some mechanism is needed to reheat this post-inflationary state, leaving a hot, thermal, radiation-dominated Universe.…
We present a new scenario for the development of the Universe after the Big Bang, built on the conjecture that a vast majority of the primordial quark matter did not undergo a phase transition to normal nuclear matter, but rather split up…
We examine the non-equilibrium time evolution of the hadronic plasma produced in a relativistic heavy ion collision, assuming a spherical expansion into the vacuum. We study the $O(4)$ linear sigma model to leading order in a large-$N$…
We discuss how primordial (e.g. inflationary) non-Gaussianity in the cosmological perturbations is left imprinted in the Large-Scale Structure of the universe. Our findings show that the information on the primordial non-Gaussianity set on…
General relativity predicts a singularity in the beginning of the universe being called big bang. Recent developments in loop quantum cosmology avoid the singularity and the big bang is replaced by a big bounce. A classical theory of…
We discuss the various physics aspects of hypothetical, coherent excitations of the pion field caused by spontaneously generated local distortions of the chiral order parameter. Such distortions, which may occur in the expansion of a hot…
The total lepton asymmetry $l=\sum_f l_f$ in our universe is only poorly constrained by theories and experiments. It might be orders of magnitudes larger than the observed baryon asymmetry $b\simeq {\cal O}(10^{-10})$, $|l|/b \leq {\cal…
In the standard big bang model the universe starts in a radiation dominated era, where the gravitational perturbations are described by second order differential equations, which will generally have two orthogonal set of solutions. One is…
Two extensions of ideas lying in the basis of the inflationary scenario of the early Universe and their effect on the large scale structure of the present-day Universe are discussed. The first of them is the possibility of fast phase…
Over the past three years we have determined the basic features of our Universe. It is spatially flat; accelerating; comprised of 1/3 a new form of matter, 2/3 a new form of energy, with some ordinary matter and a dash of massive neutrinos;…
If detected, dark matter particles such as WIMPs and sterile neutrinos will be the earliest relics we can study, the first coming from before Big Bang Nucleosynthesis, an epoch from which we have no data so far. Here we discuss how…
A model with N species of massless fermions interacting via (microscopic) gravitational torsion in de Sitter spacetime is investigated in the limit N->infinity. The U_V(N)*U_A(N) flavor symmetry is broken dynamically irrespective of the…