Related papers: Resurrecting Gravitational Vector Modes and their …
A set of equations describing the motion of a free magnetic nanoparticle in an external magnetic field in a vacuum, or in a medium with negligibly small friction forces is postulated. The conservation of the total particle momentum, i.e.…
Bulk motions of electrons along the line of sight induce secondary temperature fluctuations in the post-decoupling, reionized universe. In the presence of a magnetic field not only the scalar mode but also the vector mode act as a source…
The origin of the observed large scale magnetic fields in the Universe is a mystery. The seed of these magnetic fields has been attributed to physical process in the early universe. In this work we provide a mechanism for the generation of…
We study the production, spectrum and detectability of gravitational waves in models of the early Universe where first order phase transitions occur during inflation. We consider all relevant sources. The self-consistency of the scenario…
The detection of primordial B-mode polarization is still challenging due to the relatively low amplitude compared to the galactic foregrounds. To remove the contribution from the foreground, a comprehensive picture of the galactic magnetic…
The conformal symmetry of the quantized electromagnetic field breaks down in curved space-time. We point out that this conformal anomaly is able to generate a sizable magnetic field during a phase of slow-roll inflation. Such primordial…
Spatially fluctuating primordial magnetic fields (PMFs) inhomogeneously reheat the Universe when they dissipate deep inside the horizon before recombination. Such an energy injection turns into an additional photon temperature perturbation.…
Recently, there are several reports that the cosmic magnetic fields on Mpc scale in void region is larger than $\sim 10^{-15}$G with an uncertainty of a few orders from the current blazar observations. On the other hand, in inflationary…
We study the possibility of generating magnetic fields during the evolution of electron, proton, and photon plasma in the pre-recombination era. We show that a small magnetic field can be generated in the second order of perturbation theory…
Possible signatures of primordial magnetic fields on the Cosmic Microwave Background (CMB) temperature and polarization anisotropies are reviewed. The signals that could be searched for include excess temperature anisotropies particularly…
The time evolution of collective modes in an expanding ultarelativistic and (effectively) Abelian plasma is studied in the hard-loop approximation semi-analytically by means of integro-differential equations. A previous treatment is…
Magnetic fields observed across cosmic scales are difficult to explain within conventional physics. A primordial origin is, thus, often assumed. While a nonminimal coupling of the inflaton with the electromagnetic field could theoretically…
If the seed magnetic fields exist in the early Universe, tensor components of their anisotropic stresses are not compensated prior to neutrino decoupling and the tensor metric perturbations generated from them survive passively.…
We demonstrate generation of chiral modes -- vortex flows with fixed handedness in exciton-polariton quantum fluids. The chiral modes arise in the vicinity of exceptional points (non-Hermitian spectral degeneracies) in an optically-induced…
While a specific kind of strange metal is increasingly found to be the "normal" states in a wide variety of unconventional superconductors, its microscopic origin is presently a hotly debated enigma. Using dynamical mean-field theory (DMFT)…
Cosmological magnetic fields in open Friedmann universes can experience superadiabatic amplification within the realm of conventional electromagnetism. This is possible mathematically, despite the conformal invariance of Maxwell's…
In this work, we develop a generic formalism for the study of tensor perturbations induced at second order by first-order vector metric perturbations, dubbing these induced tensor modes $\textit{vector-induced gravitational waves}$ (VIGWs).…
A first-order phase transition in the early universe can give an observable stochastic gravitational background (SGWB), which will necessarily have primordial anisotropies across the sky. In multi-field inflationary scenarios, these…
We performed three-dimensional magnetohydrodynamic simulations of shear Alfven waves in a full field line system with magnetosphere-ionosphere coupling and plasma non-uniformities. Feedback instability of the Alfven resonant modes showed…
We reconsider the enhancement of primordial gravitational waves that arises from a quantum gravitational model of inflation. A distinctive feature of this model is that the end of inflation witnesses a brief phase during which the Hubble…