相关论文: Robust Limits on Photon Mass from Statistical Samp…
Proposed close-encounter solar probes (Vulcan and Solar Probe) are planned to have highly eccentric orbits, with a perihelion of about $4R_S$ and an inclination close to $90^\circ$ out of the plane of the ecliptic. We show this could allow…
We provide an empirical list of the Galactic dispersion measure ($DM_{Gal}$) contribution to the extragalactic fast radio bursts along 72 sightlines. It is independent of any model of the Galaxy, i.e., we do not assume the density of the…
Conventional theories of electromagnetic waves in a medium assume that the energy propagating with the light pulse in the medium is entirely carried by the field. Thus, the possibility that the optical force field of the light pulse would…
We calculate the rate of production of dark photons from electron-positron pair annihilation in hot and dense matter characteristic of supernova progenitors. Given the non-linear dependence of the emission rate on the dark photon mass and…
The deflection of a laser beam traveling through a modulated electric field is measured using phase-sensitive detection to place an upper bound on photon charge. An upper limit of $10^{-14}e$ is obtained. The experiment involves a number of…
A limit on a possible cosmological variation of the proton-to-electron mass ratio $\mu$ is derived from methanol (CH$_3$OH) absorption lines in the benchmark PKS1830$-$211 lensing galaxy at redshift $z = 0.89$ observed with the Effelsberg…
Photon-photon scattering, due to photons interacting with virtual electron-positron pairs, is an intriguing deviation from classical electromagnetism predicted by quantum electrodynamics (QED). Apart from being of fundamental interest in…
We investigate properties of Galactic microlensing events in which a stellar object is lensed by a neutron star. For an all-sky photometric microlensing survey, we determine the number of lensing events caused by $\sim10^{5}$…
If the photon possessed a nonzero charge, then electromagnetic waves traveling along different paths would acquire Aharonov-Bohm phase differences. The fact that such an effect has not hindered interferometric astronomy places a bound on…
The recent measurement of the Shapiro delay in the radio pulsar PSR J1614-2230 yielded a mass of 1.97 +/- 0.04 M_sun, making it the most massive pulsar known to date. Its mass is high enough that, even without an accompanying measurement of…
In addition to its relevant astrophysical and cosmological significance, the Extragalactic Background Light (EBL) is a fundamental source of opacity for cosmic high energy photons, as well as a limitation for the propagation of high-energy…
We calculate the intergalactic photon density as a function of both energy and redshift for 0 < z < 6 for photon energies from .003 eV to the Lyman limit cutoff at 13.6 eV in a Lambda-CDM universe with $\Omega_{\Lambda} = 0.7$ and…
It is argued that if extragalactic magnetic fields are smaller than 2x10^{-12} G the flux of ultra-high energy photons of (a few)x10^{-1} eV cm^{-2}s^{-1}sr^{-1} predicted in the top-down models of UHE CR implies similar flux of the diffuse…
Studies of the Galactic population of radio pulsars have shown that their luminosity distribution appears to be log-normal in form. We investigate some of the consequences that occur when one applies this functional form to populations of…
Radio pulsars emit regular bursts of radio radiation that propagate through the interstellar medium (ISM), the tenuous gas and plasma between the stars. Previously known dispersive properties of the ISM cause low frequency pulses to be…
The inertial and gravitational mass of electromagnetic radiation (i.e., a photon distribution) in a cavity with reflecting walls has been treated by many authors for over a century. After many contending discussions, a consensus has emerged…
Correlations between the arrival time and the energy of photons emitted in outbursts of astrophysical objects are predicted in quantum and classical gravity scenarios and can appear as well as a result of complex acceleration mechanisms…
We predict from a survey of equations of state and observations of X-ray pulsations from SAX J1808.4-3658, that the upper limit of the mass of the compact star is 2.27 solar mass. The corresponding upper limit of the radius comes out to be…
We demonstrate that CPT-violation due to $e^+ e^-$ mass difference generates a non-zero photon mass. As a result the cosmological bounds on the photon mass lead to the bounds on $e^+ e^-$ mass difference which are at least by 10 orders of…
Many quantum gravity theories imply that the vacuum is filled with virtual black holes. This paper explores the process in which high energy photons interact with virtual black holes and decay into gravitons and photons of lower energy. The…