相关论文: Nearly Minimal Magnetogenesis
We explore a mechanism to produce a light dark photon dark matter through a coupling between the dark photon field and a spectator scalar field which plays no role in the inflationary expansion of the Universe while rolling down its…
We propose a novel mechanism to generate primordial magnetic fields (PMFs) strong enough to explain the observed cosmic magnetic fields. We employ a scalar field charged under U(1) gauge symmetry with a non-trivial VEV to provide an…
The power spectrum of the cosmic microwave background from both the Planck and WMAP data exhibits a slight dip in for multipoles in the range of l=10-30. We show that such a dip could be the result of resonant creation of a massive particle…
Recently, attempts have been made to understand the apparent near coincidence of the present dark energy and matter energy in terms of a dynamical attractor-like solution for the evolution of a scalar field. In these models the field…
Generation of primordial magnetic fields during inflation typically requires the breaking of conformal invariance of the Electromagnetic action. In this paper this has been achieved naturally in a higher dimensional cosmological model with…
We consider the amplification of electromagnetic quantum vacuum fluctuations induced by the presence of metric perturbations at the end of inflation. We obtain the amplitude of the corresponding magnetic fields on super-Hubble scales and…
We propose a new model-independent mechanism for producing primordial black holes from a period of multi-field inflation. This requires an enhancement of primordial fluctuations at short scales compared to their value at CMB scales. We show…
We study the primordial magnetic field generated by stochastic currents produced by scalar charged particles created at the beginning of the radiation dominated epoch. We find that for the mass range 10^(-6)GeV \leq m \leq 10^2 GeV, a field…
We propose an inflationary scenario, M-flation, in which inflation is driven by three $N\times N$ hermitian matrices $\Phi_i, i=1,2,3$. The inflation potential of our model, which is strongly motivated from string theory, is constructed…
We study the magnetic field generation in a neutron star within the model based on the magnetic field instability in the nuclear matter owing to the electron-nucleon parity violating interaction. We suggest that the growing magnetic field…
The primordial density fluctuation inevitably couples to all forms of matter via loop corrections and depends on the ambient conditions while inflation was ongoing. This gives us an opportunity to observe processes which were in progress…
We show that breaking of the conformal invariance of electromagnetic Lagrangian which is required for inflationary magnetogenesis arises naturally in the Poincar{\'e} Gauge Theory. We use the minimal coupling prescription to introduce the…
We estimate the strength of large-scale magnetic fields produced during inflation in the framework of Dirac-Born-Infeld (DBI) theories. This analysis is sufficiently general in the sense that it covers most of conformal symmetry breaking…
We present a simple model where a scalar field is responsible for cosmic inflation and generates the seed for structure formation, while its thermal relic abundance explains dark matter in the universe. The inflaton self-coupling also…
An oscillating inflaton field induces small amplitude oscillations of the Hubble parameter at the end of inflation. These Hubble parameter induced oscillations, in turn, trigger parametric particle production of all light fields, even if…
In the framework of mixed Higgs-Starobinsky inflation, we consider the generation of Abelian gauge fields due to their nonminimal coupling to gravity (in two different formulations of gravity -- metric and Palatini). We couple the…
We show that strong magnetic fields can be generated at shock waves associated with formation of galaxies or clusters of galaxies by the Weibel instability, an instability in collisionless plasmas. The estimated strength of the magnetic…
The existence of large-scale magnetic fields in galaxies is well established, but there is no accepted mechanism for generating a primordial field which could grow into what is observed today. We discuss a model which attempts to account…
We study models of inflation where the inflaton corresponds to a flat direction in field space and its mass term is generated by gravity mediated soft supersymmetry breaking at high scale. Assuming the inflaton to have non negligible…
We use non-linear gauge-invariant perturbation theory to study the interaction of an inflation produced seed magnetic field with density and gravitational wave perturbations in an almost Friedmann-Lema\^itre-Robertson-Walker (FLRW)…