相关论文: The Impact of Particle Production on Gravitational…
We study production of light particles due to oscillation of the Hubble parameter or the scale factor. Any coherently oscillating scalar field, irrespective of its energy fraction in the universe, imprints such an oscillating feature on…
Recent studies suggest that the process of symmetry breaking after inflation typically occurs very fast, within a single oscillation of the symmetry-breaking field, due to the spinodal growth of its long-wave modes, otherwise known as…
We study a scenario in which the baryon asymmetry is created through Hawking radiation from primordial black holes via a dynamically-generated chemical potential. This mechanism can also be used to generate the observed dark matter…
In models of inflation driven by an axion-like pseudoscalar field, the inflaton, a, may couple to the standard model hypercharge via a Chern-Simons-type interaction, $L \subset a/(4\Lambda) F\tilde{F}$. This coupling results in explosive…
Generation of adiabatic density perturbations from fluctuations caused by the birth of baryons is considered. This is based on the scenario of baryogenesis in which the birth of protons takes place at the temperature equal to the mass of…
The mechanism behind the generation of the baryon asymmetry of the Universe (BAU) is one of the biggest open questions of (astro-)particle physics. Popular mechanisms to generate the observed baryon asymmetry include CP-violating…
Particle phase transitions in the early universe including electroweak and grand unification ones are well-studied subjects. We point out that there are new possible particle phase transitions around inflation. Those new inflationary…
We analyze cosmological particle production driven by spacetime expansion in the early universe for homogeneous and isotropic cosmologies with positive, negative, and zero spatial curvature. We prioritize analytical results to gain a deeper…
Gravitational leptogenesis refers to a class of baryogenesis models in which the matter-antimatter asymmetry of the universe arises through the standard model lepton-number gravitational anomaly. In these models chiral gravitational waves…
It is investigated whether a massive Abelian vector field, whose gauge kinetic function is growing during inflation, can be responsible for the generation of the curvature perturbation in the Universe. Particle production is studied and it…
Baryogenesis refers to the theoretical process that occurred in the early history of the universe producing excess of matter over antimatter. Hitherto, fundamental physics which can give rise to such events is unknown. Many theories have…
We consider baryogenesis in quantum fluctuation modified gravity. We explore three forms (two are newly proposed here) of baryogenesis interaction and discuss the effect of these interaction terms on the baryon-to-entropy ratio during the…
Previous numerical investigations of gravitational particle production during the coherent oscillation period of inflation displayed unexplained fluctuations in the spectral density of the produced particles. We argue that these features…
In the purely gravitational dark matter scenario, the dark matter particle does not have any interaction except for gravitational one. We study the gravitational particle production of dark matter particle in such a minimal setup and show…
We investigate the gravitational production of scalar dark matter particles during the inflationary and reheating epochs. The oscillatory behavior of the curvature scalar $R$ during the reheating phase generates two different enhancement…
In models with the fundamental gravity scale in the TeV range, early cosmology is quite different from the standard picture, because the universe must have arisen at a much lower temperature and the electroweak symmetry was probably never…
We explore the possibility of baryogenesis in the framework of quintessential inflation. We focus on the model independent features of the underlying paradigm and demonstrate that the required baryon asymmetry can successfully be generated…
The impact of particle production during inflation on the primordial curvature perturbation spectrum is investigated both analytically and numerically. We obtain an oscillatory behavior on small scales, while on large scales the spectrum is…
Rotations of an axion field in field space provide a natural origin for an era of kination domination, where the energy density is dominated by the kinetic term of the axion field, preceded by an early era of matter domination. Remarkably,…
We study scenarios in which the baryon asymmetry is generated from the decay of a particle whose mass originates from the spontaneous breakdown of a symmetry. This is realized in many models, including low-scale leptogenesis and theories…