Relativistic Effects of Rotation in γ-ray Pulsars—Invited Review

Abstract

In this paper, we consider the relativistic effects of rotation in the magnetospheres of γ-ray pulsars. The paper reviews the progress achieved in this field during the last three decades. For this purpose, we examine the direct centrifugal acceleration of particles and the corresponding limiting factors: the constraints due to the curvature radiation and the inverse Compton scattering of electrons against soft photons. Based on the obtained results, the generation of parametrically excited Langmuir waves and the corresponding Landau–Langmuir centrifugal drive are studied.

Prospects of SETI by small size optical telescopes

“…As it has been studied in detail by (Wright 2020) it is unrealistic to construct a monolithic spherical megastructure, because no material can be stable against internal gravitational stresses, implying that DSs should be composed of concentric rings. Then, one can show that the radius of the ring is given by (Osmanov and Berezhiani 2019;Osmanov 2021)…”

“…Another interesting feature the observational signatures of megastructures will be characterised is the spectral variability. Osmanov and Berezhiani (2019) and Osmanov (2021) have examined ringlike megastructures around stars and pulsars and it was found that the hot rings oscillate nearby equilibrium positions leading (via the Doppler shift) to the spectral variability. The corresponding time-scales vary from several minutes (M-type stars) up to years (O-type stars).…”

A Novel Mechanism of Pair Creation in Pulsar Magnetospheres

“…Efficiency of centrifugal force depends on the configuration of magnetic field lines; the particles slide on. For example, if the force free approximation (curved field lines) is valid, efficiency will be relatively low [13], whereas for almost straight field lines, energies of centrifugally accelerated particles will be very high [14]. The transition to the force-free regime takes place in a very thin zone near the LC and most of the time particles accelerate on almost rectilinear co-rotating magnetic field lines [14].…”

“…For example, if the force free approximation (curved field lines) is valid, efficiency will be relatively low [13], whereas for almost straight field lines, energies of centrifugally accelerated particles will be very high [14]. The transition to the force-free regime takes place in a very thin zone near the LC and most of the time particles accelerate on almost rectilinear co-rotating magnetic field lines [14]. As has been shown in [15] the centrifugal force in the LC area is different for different species of particles (magnetospheric electrons and positrons).…”

“…This in turn might lead to charge separation creating the Langmuir waves. On the other hand, since the centrifugal force is time dependent [15], it acts as a parameter and the driven electrostatic field is parametrically amplified [14][15][16][17][18]. In a recent study [19], it was shown that the mentioned mechanism might lead to extremely efficient heating of AGN magnetospheres.…”