Related papers: Stochastic background of gravitational waves from …
Light waves carry along their own gravitational field; for simple plain electromagnetic waves the gravitational field takes the form of a pp-wave. I present the corresponding exact solution of the Einstein-Maxwell equations and discuss the…
Phase transitions in the early universe can readily create an observable stochastic gravitational wave background. We show that such a background necessarily contains anisotropies analogous to those of the cosmic microwave background (CMB)…
Radio, X-ray and infrared observations of the inner few hundred pc of the Galactic center have highlighted two characteristics to the ISM. The cosmic ray ionization rate derived from molecular ions such as H$^+_3$, is at least two to three…
We offer a physical interpretation of the origin of the scalar-induced gravitational wave background, showing that it is mainly produced around the peaks of the scalar perturbations. We also provide a compact expression to estimate the…
We investigate the gravitational wave background produced by magnetars. The statistical properties of these highly magnetized stars were derived by population synthesis methods and assumed to be also representative of extragalactic objects.…
High-Reynolds-number turbulence driven by stellar convection in main-sequence stars generates stochastic gravitational radiation. We calculate the wave-strain power spectral density as a function of the zero-age main-sequence mass for an…
The geometric optics approximation traditionally used to study the propagation of gravitational waves on a curved background, breaks down in the vicinity of compact and extended astrophysical objects, where wave-like effects like diffusion…
Global cosmic strings are generically predicted in particle physics beyond the Standard Model, e.g., a post-inflationary global $U(1)$ symmetry breaking which may associate with axion-like dark matter. We demonstrate that although…
We consider an alternative approach for the computation of the stochastic gravitational wave background generated by small loops produced throughout the cosmological evolution of cosmic string networks and use it to derive an analytical…
Gravitational radiation is an elusive form of radiation predicted by general relativity, it is the subject of intense theoretical and experimental research at the limit of the sensitivity of today's instrumentation. In spite of the fact…
Stochastic gravitational waves (GW) associated with unresolved astrophysical sources at frequency bands of the ongoing GW interferometers LIGO/VIRGO and LISA are studied. We show that GW noise from rotating galactic neutron stars with low…
In the weak field regime, gravitational waves can be considered as being made up of collisionless, relativistic tensor modes that travel along null geodesics of the perturbed background metric. We work in this geometric optics picture to…
The origin and acceleration of high-energy particles in space (cosmic rays), constitute important topics in modern astrophysics. Among the The origin and acceleration of high-energy particles, constituting cosmic rays, is likely to remain…
We review some of the properties of extensive cosmic ray air showers and describe a simple model of the radio-frequency radiation generated by shower electrons and positrons as they bend in the Earth's magnetic field. We perform simulations…
We study graviton-photon conversion in the presence of stochastic magnetic fields. Assuming Gaussian magnetic fields that may possess nontrivial helicity, and unpolarized gravitational waves (GWs) as the initial state, we obtain expressions…
The origin of the extragalactic gamma-ray background is a pressing cosmological mystery. The Fermi Gamma-Ray Space Telescope has recently measured the intensity and spectrum of this background; both are substantially different from previous…
We argue that gamma-ray bursts (GRBs) may be the origin of the cosmic gamma-ray background radiation observed in GeV range. It has theoretically been discussed that protons may carry a much larger amount of energy than electrons in GRBs,…
We investigate the influence of a gravitational wave background on particles in circular motion. We are especially interested in waves leading to stationary orbits. This consideration is limited to circular orbits perpendicular to the…
The interaction between gravitational and electromagnetic radiation has a rather long research history. It is well known, in particular, that gravity-wave distortions can drive propagating electromagnetic signals. Since forced oscillations…
The background of gravitational waves produced by the ensemble of rotating neutron stars (which includes pulsars, magnetars and gravitars) is investigated. A formula for \Omega(f) (commonly used to quantify the background) is derived,…