Related papers: Analytic Approximations for Fermionic Preheating
We propose a new scenario to produce the superheavy dark matter based on the inflationary universe. In our scenario, the inflaton couples to both a boson and a stable fermion. Although the fermion is produced by the inflaton decay after…
We summarize three recent efforts to constrain the first few moments of cosmic creation before and during the epoch of inflation. We consider two means to explain a slight dip in the power spectrum of the cosmic microwave background for…
As a toy model for dynamics in nonequilibrium quantum field theory we consider the abelian Higgs model in 1+1 dimensions with fermions. In the approximate dynamical equations, inhomogeneous classical (mean) Bose fields are coupled to…
We investigate the particle production due to parametric resonances in model of inflation where the lightest composite state stemming from the minimal walking technicolor theory plays the role of the inflaton. For model of inflation, the…
Non-observation of any dark matter signature at various direct detection experiments over the last decade keeps indicating that immensely popular WIMP paradigm may not be the actual theory of particle dark matter. Non-thermal dark matter…
Preheating after inflation proceeds through parametric resonance, leading to efficient particle production in scalar field models. In this work, we investigate the structure of parametric resonance in the $\phi^4$ chaotic inflationary model…
Gravitational dark matter (DM) is the simplest possible scenario that has recently gained interest in the early universe cosmology. In this scenario, DM is assumed to be produced from the decaying inflaton through the gravitational…
Quantum fluctuations created during inflation can account for the observed matter distribution in the linear regime if the universe has two components of dark matter, one which is cold and collisionless, and the other which is hot and free…
In a variety of inflation models the motion of the inflaton may trigger the production of some non-inflaton particles during inflation, for example via parametric resonance or a phase transition. Particle production during inflation leads…
We investigate warm inflation in the framework of $f(Q)$ gravity within a Friedmann-Robertson-Walker spacetime. Unlike cold inflation, where the inflaton evolves in isolation, warm inflation features continuous interaction between the…
Out-of-equilibrium fermions can be created in the early Universe by non-perturbative parametric effects, both at preheating or during the thermal era. An anisotropic stress is developed in the fermion distribution, acting as a source of a…
We study in this paper the properties of a gas of fermions interacting {\em via} a scalar potential $v(q)=4\pi{e}^2/q^2$ for $q<\Lambda<<k_F$ at dimensions larger than one, where $\Lambda$ is a high momentum cutoff and $k_F$ is the fermi…
We consider the simplest possibility for a model of particle dark matter in which dark matter has only gravitational interaction with the standard model sector. Even in such a case, it is known that the gravitational particle production in…
The rate for the production of a pair of massive fermions in $e^+ e^-$ annihilation plus real or virtual radiation of a pair of massless fermions is calculated analytically. The contributions for real and virtual radiation are displayed…
We develop a method to obtain fermion spectral functions non-perturbatively in a non-Abelian gauge theory with high occupation numbers of gauge fields. After recovering the free field case, we extract the spectral function of fermions in a…
We investigate the temperature-dependent production of feebly interacting massive dark matter particle (FIMP DM) within a $Z_2$ model, incorporating two $Z_2$-odd scalar fields. In specific parameter regions, three distinct mechanisms…
We show that when the QCD axion is directly coupled to quarks with $c_q/f \, \partial_\mu a \, \bar{q} \gamma^\mu \gamma^5 q$, such as in DFSZ models, the dominant production mechanism in the early universe at temperatures $1 \, {\rm…
The process of fermion production in the field of a magnetic dipole on a de Sitter expanding universe is analyzed. The amplitude and probability for production of massive fermions are obtained using the exact solution of the Dirac equation…
We present a complete computation of the inflaton decay into very massive fermions during preheating. We show that heavy fermions are produced very efficiently up to masses of order 10^{17}-10^{18} GeV; the accessible mass range is thus…
Axion-like degrees of freedom generally interact with fermions through a shift symmetric coupling. As a consequence, a time-dependent axion will lead to the generation of fermions by amplifying their vacuum fluctuations. We provide the…