Related papers: Cosmological implications of supersymmetric axion …
Cosmological bounds on neutrinos and additional hypothetical light thermal relics, such as QCD axions, are currently among the most restrictive ones. These limits mainly rely on Cosmic Microwave Background temperature anisotropies.…
The dark dimension scenario, which is motivated from Swampland principles and predicts a single micron scale extra dimension, suggests a consistent framework for the dark sector of the universe. We consider the implications of this scenario…
We examine axino dark matter in the regime of a low reheating temperature T_R after inflation and taking into account that reheating is a non-instantaneous process. This can have a significant effect on the dark matter abundance, mainly due…
The thermal history of the universe before the epoch of nucleosynthesis is unknown. The maximum temperature in the radiation-dominated era, which we will refer to as the reheat temperature, may have been as low as 0.7 MeV. In this paper we…
We propose a model of dynamical relaxation of the cosmological constant. Technical naturalness of the model and the present value of the vacuum energy density imply an upper bound on the supersymmetry breaking scale and the reheating…
We consider an extension of the radiative neutrino mass model at TeV regions so as to give the origin for inflation of the universe. This extension also gives a consistent explanation for both the origin of baryon number asymmetry and dark…
If axions exist, they are copiously produced in hot and dense plasmas, carrying away energy directly from the interior of stars. Various astronomical observables constrain the operation of such anomalous stellar energy-loss channels and…
Future CMB experiments have the potential to probe the density of relativistic species at the sub-percent level. Sensitivity at this level allows light thermal relics to be detected up to arbitrarily high decoupling temperatures.…
Cosmological structure formation simulations of ultralight axion-like dark matter have shown that an axion star forms at the center of every dark matter halo in the Universe. These axion stars would then form in large numbers during the…
Axions arise in many theoretical extensions of the Standard Model of particle physics, in particular the "string axiverse". If the axion masses, $m_a$, and (effective) decay constants, $f_a$, lie in specific ranges, then axions contribute…
Cosmic topological defects in a wide class of supersymmetric theories can simultaneously be sources of higgs particles of mass comparable to the supersymmetry breaking scale $\sim$ TeV, as well as superheavy gauge bosons of mass $\sim\eta$,…
Axions with variable masses, in the context of a scalar--tensor gravity theory, give a large entropy production during the matter era. The subsequent axion dilution is proportional to their present energy density. Depending on the…
We consider cosmological consequences of a heavy axino, decaying to the neutralino in R-parity conserving models. The importance and influence of the axino decay on the resultant abundance of neutralino dark matter depends on the lifetime…
Various theoretical and experimental considerations motivate models with high scale supersymmetry breaking. While such models may be difficult to test in colliders, we propose looking for signatures at much lower energies. We show that a…
1. Introduction 2. Models: the QCD axion; the strong CP problem; PQWW, KSVZ, DFSZ; anomalies, instantons and the potential; couplings; axions in string theory 3. Production and I.C.'s: SSB and non-perturbative physics; the axion field…
Cosmological evolution of axion field in the early universe might be significantly affected by a thermal friction induced by the axion coupling to thermalized hidden sector. We examine the effects of such a thermal friction on axion dark…
Axions, and axion-like particles, have come back into fashion in the last decades as a possible solution to the galactic-scale crisis suffered by the cold dark matter model. In the framework of the wave Dark Matter model, we have carried…
We study the potential of a future, large-volume photometric survey to constrain the axion mass $m_a$ in the hot dark matter limit. Future surveys such as Euclid will have significantly more constraining power than current observations for…
We give a systematic discussion of the contributions to the cosmological energy density in axions from vacuum realignment, string decay and wall decay. We call these the cold axion populations because their kinetic energy per particle is at…
We present updated constraints on the parameters of an axion dark energy model, for which we took into account the properties of its characteristic potential and its full cosmological evolution. We show that the values of the axion…