arXiv subjects

Zhenyun Fang

Publications and source records attributed to Zhenyun Fang.

3 recordsLinked to original sources

arXiv2017

Very high frequency gravitational waves from magnetars and gamma-ray burst

Extremely powerful astrophysical electromagnetic (EM) system could be possible source of high-frequency gravitational waves (HFGWs). Here based on properties of magnetars and gamma-ray bursts (GRBs), we address "Gamma-HFGWs" (with very high-frequency around 10^{20}Hz) caused by ultra-strong EM radiations (in the radiation-dominated phase of GRBs fireball) interacting with super-high magnetar surface magnetic fields (around 10^{11}Tesla). By certain parameters of distance and power, the Gamma-HFGWs would have far field energy density around 10^{-6}, and they would cause perturbed signal EM waves of around 10^{-20}Watt/m^2 in planned HFGW detection system based on EM response to GWs. Specially, Gamma-HFGWs would possess distinctive envelopes with characteristic shapes depending on the particular structures of surface magnetic fields of magnetars, which could be exclusive features helpful to distinguish them from background noise. Results obtained suggest that magnetars could involve in possible astrophysical EM sources of GWs in very high-frequency band, and Gamma-HFGWs would be potential targets for observations in the future.

gr-qc↗

arXiv2017

Quasi-B-mode generated by high-frequency gravitational waves and corresponding perturbative photon fluxes

Interaction of very low-frequency primordial(relic) gravitational waves(GWs) to cosmic microwave background(CMB) can generate B-mode polarization. Here, for the first time we point out that the electromagnetic(EM) response to high-frequency GWs(HFGWs) would produce quasi-B-mode distribution of the perturbative photon fluxes, and study the duality and high complementarity between such two B-modes. Based on this quasi-B-mode in HFGWs, it is shown that the distinguishing and observing of HFGWs from the braneworld would be quite possible due to their large amplitude, higher frequency and very different physical behaviors between the perturbative photon fluxes and background photons, and the measurement of relic HFGWs may also be possible though face to enormous challenge.

gr-qc↗

arXiv2008

Perturbative Photon Fluxes Generated by High-Frequency Gravitational Waves and Their Physical Effects

We consider the electromagnetic (EM) perturbative effects produced by the high-frequency gravitational waves (HFGWs) in the GHz band in a special EM resonance system, which consists of fractal membranes, a Gaussian beam (GB) passing through a static magnetic field. It is predicted, under the synchroresonance condition, coherence modulation of the HFGWs to the preexisting transverse components of the GB produces the transverse perturbative photon flux (PPF),which has three novel and important properties: (1)The PPF has maximum at a longitudinal symmetrical surface of the GB where the transverse background photon flux (BPF) vanishes; (2) the resonant effect will be high sensitive to the propagating directions of the HFGWs; (3) the PPF reflected or transmitted by the fractal membrane exhibits a very small decay compared with very large decay of the much stronger BPF. Such properties might provide a new way to distinguish and display the perturbative effects produced by the HFGWs. We also discuss the high-frequency asymptotic behavior of the relic GWs in the microwave band and the positive definite issues of their energy-momentum pseudo-tensor.

gr-qc↗