Related papers: Electromagnetic Radiation from Binary Stars Mediat…
As first noted by Robert Wagoner in the 1970s, if a scalar field is nonminimally coupled to the Ricci scalar and propagates at subluminal speeds, then there exists the possibility of scalar $\check{\hbox{C}}$erenkov radiation from a moving…
We study quasi-equilibrium sequences of binary neutron stars in the framework of Damour-Esposito-Farese-type scalar-tensor theory of gravity with a massive scalar field, paying particular attention to the case where neutron stars are…
Magnetic fields inside and around neutron stars are at the heart of pulsar magnetospheric activity. Strong magnetic fields are responsible for quantum effects, an essential ingredient to produce leptonic pairs and the subsequent broadband…
We consider the spectrum, emissivity and flux of the electromagnetic radiation emitted by the thin electron layer (the electrosphere) at the surface of a bare strange star. In particular, we carefully consider the effect of the multiple and…
Eclipsing binaries are vital for directly determining stellar parameters without reliance on models or scaling relations. Spectroscopically derived parameters of detached and semi-detached binaries allow us to determine component masses…
The vacuum polarization in an external gravitational field due to one loop electron-positron pair and one loop millicharged fermion-antifermion pair is studied. Considering the propagation of electromagnetic (EM) radiation and gravitational…
Electromagnetic duality is discussed in the context of Einstein-Maxwell-scalar (EMS) models including axionic-type couplings. This family of models introduces two non-minimal coupling functions $f(\phi)$ and $g(\phi)$, depending on a real…
When the magnetosphere of a magnetar is perturbed by crustal deformation, an electric field $E_\parallel$ parallel to the magnetic field line would appear via Alvf\'en waves in the charge starvation region. The electron-positron pair…
We calculate the power emitted in scalar modes for a binary systems, including binary pulsars, with a conformal coupling to the most general Galileon effective field theory by considering perturbations around a static, spherical background.…
We consider a system rotating at extremely high angular velocity, so that its matter is found mostly at the light-cylinder. We posit that it can be described by quantum fields confined to the two-dimensional cylindrical surface rotating…
We develop a full four-dimensional numerical code to study scalar gravitational radiation emitted from binary systems and probe the Vainshtein mechanism in situations that break the static and spherical symmetry, relevant for binary pulsars…
The background motivation, and some preliminary results, are reported for a recently begun investigation of a potentially important mechanism for electromagnetic radiation from space, Double Layer Radiation (DL-radiation). This type of…
We consider the polarization characteristics of the electromagnetic (EM) counterpart of the gravitational wave (GW) created by coalescence of the binary sources. Here, we explore the impact of the photon-graviton interaction on the…
Binary neutron star mergers provide a laboratory for probing fundamental physics through their gravitational-wave emission and electromagnetic counterparts. In particular, they may allow us to explore signatures of physics beyond the…
We model the effect of photon and ultra-light pseudoscalar mixing on the propagation of electromagnetic radiation through the extragalactic medium. The medium is modelled as a large number of magnetic domains, uncorrelated with one another.…
We consider the scenario where dark matter (DM) is represented by an ultra-light classical scalar field performing coherent periodic oscillations. We point out that such DM perturbs the dynamics of binary systems either through its…
According to Einstein-Maxwell-Dilaton theory, the dilaton field $\psi$ can be produced by electromagnetic fields with non-zero Maxwell invariant. So electromagnetic wave propagating in an external electromagnetic field is a typical source…
The polarization of radiation by scattering on an atom embedded in combined external quadrupole electric and uniform magnetic fields is studied theoretically. Limiting cases of scattering under Zeeman effect and Hanle effect in weak…
We investigate the effects of the magnetic dipole-dipole coupling and the electromagnetic radiation on the frequency evolution of gravitational waves from inspiralling binary neutron stars with magnetic dipole moments. This study is…
We solve the general problem of mixing of electromagnetic and scalar or pseudoscalar fields coupled by axion-type interactions ${\cal L}_{int} =g_{\phi} \phi \epsilon_{\mu \nu \a \b}F^{\mu \nu}F^{\a \b} $. The problem depends on several…