Narrow Results

In this paper, we study the self-force in the Parikh–Wilczek tunneling model of Hawking radiation for Reissner–Nordström (RN) black holes. We conclude that the repulsive self-force speeds up the emission and the radiation becomes an irreversible process. We also find an upper bound of charge–mass ratio for emitted particles.

In this paper, we discuss a mode sum regularization method for the self-force acting on a charged test particle moving around a Banados, Teitelboim and Zanelli (BTZ) black hole. First, we have calculated the self-force on each individual mode. Then we evaluated our result by summing up the contribution on each mode. We studied a general scheme for static black holes and then present the result for radial trajectories around $(2+1)$-dimensional charged BTZ black hole in Einstein–Gauss–Bonnet (EGB) gravity. We find that the parameter which is coupling ($2+1$) GR to Einstein–Gauss–Bonnet gravity has a significant impact on the self-force.

In this work, we study a charged particle in the presence of both a continuous distribution of disclinations and a continuous distribution of edge dislocations in the framework of the geometrical theory of defects. We obtain the self-energy for a single charge both in the internal and external regions of either distribution. For both distributions, the result in the outside region is the self-energy that a single charge experiments in the presence of a single defect.

The self-energy and self-force for particles with electric and scalar charges at rest in the space-time of massless and massive wormholes are considered. The particle with electric charge is always attracted to wormhole throat for arbitrary profile of the throat. The self-force for scalar particle shows different behavior depending on the non-minimal coupling. The self-force for massive scalar field is localized close to the throat of the wormhole.

The aim of this paper is to highlight a recently proposed method for the treatment of classical radiative effects, in particular radiation reaction, via effective field theory methods. We emphasize important features of the method and in particular the doubling of fields. We apply the method to two simple systems: a mass–rope system and an electromagnetic charge-field system. For the mass–rope system in 1 + 1 dimensions we derive a double-field effective action for the mass which describes a damped harmonic oscillator. For the EM charge-field system, i.e. the system of an accelerating electric charge in 3 + 1 dimensions, we show a reduction to a 1 + 1 dimensions radial system of an electric dipole source coupled to an electric dipole field (analogous to the mass coupled to the rope). For this system we derive a double-field effective action and reproduce in an analogous way the leading part of the Abraham–Lorentz–Dirac force.

An accelerating electric charge coupled to its own electromagnetic field both emits radiation and experiences the radiation's reaction as a (self-)force. Considering the system from an Effective Field Theory perspective, and using the physical initial conditions of no incoming radiation can help resolve many of the problems associated with the often considered "notorious" Abraham–Lorentz/Abraham–Lorentz–Dirac equations.

We compute the self-force on a scalar charge at rest in the space–time of long throat. We consider arbitrary values of the mass of the scalar field and the constant of nonminimal coupling of the scalar field to the curvature of space–time. We also show the coincidence of explicit calculations of self-force in the limit of large mass of the field with known results.

We consider a relation between the Huygens Principle (HP) in gravity and the self-interaction force. We show that the self-force for an electric particle in the plane gravitational wave space-time has no tail term even the vector Green function does not obey the HP. The reason for this observation is that even vector potential does not obey the HP, the electromagnetic field does obey.

The principle of equivalence is shown to extend to situations involving radiation reaction. For example, the Lorentz force law governs the motion of an isolated charge undergoing radiation reaction. In the case of an isolated uncharged particle of small mass, it is the geodesic equation which governs the motion, even when radiation reaction is included. For a local observer to understand such motion he must subtract the singular field of the particle from the actual electromagnetic and gravitational fields he measures. The remaining source-free fields are then used in computing the motion of the particle. With only local measurements, the observer has no knowledge of the existence of radiation and sees no effect which he would be compelled to describe as radiation reaction.

We consider the self-energy and the self-force for scalar massless particles at rest in the short-throat flat-space–time wormhole background. In some limiting cases we found how the sign of the self-energy changes with the non-minimal constant ξ. We found that the self-force is always attractive for the profile of the throat considered.

The inspiral of a stellar-mass astrophysical object into a massive black hole may be modeled within perturbation theory of General Relativity via the so-called self-force. In this paper, we present a novel method for the calculation of the self-force which is based on the Green function (GF) of the wave equation satisfied by the field created by the smaller object. We review the results in [M. Casals, S. Dolan, A. C. Ottewill and B. Wardell, Phys. Rev. D88 (2013) 044022; B. Wardell, C. R. Galley, A. Zenginoğlu, M. Casals, S. R. Dolan and A. C. Ottewill, Phys. Rev. D89 (2014) 084021] on the GF and the self-force on a scalar charge (as a model for the gravitational case) moving on a Schwarzschild black hole spacetime. This GF method offers an appealing geometrical insight into the origin of the self-force and is a promising candidate for practical self-force calculations.

Obviously, in Galilean physics, the universality of free fall implies an inertial frame, which in turns implies that the mass $m$ of the falling body is omitted (because it is a test mass; put otherwise, the center of mass of the system coincides with the center of the main, and fixed, mass $M$; or else, we consider only a homogeneous gravitational field). Conversely, an additional (in the opposite or same direction) acceleration proportional to $m/M$ would rise either for an observer at the center of mass of the system, or for an observer at a fixed distance from the center of mass of $M$. These elementary, but overlooked, considerations fully respect the equivalence principle (EP) and the (local) identity of an inertial or a gravitational pull for an observer in the Einstein cabin. They value as fore-runners of the self-force and gauge dependency in general relativity. Because of its importance in teaching and in the history of physics, coupled to the introductory role to Einstein’s EP, the approximate nature of Galilei’s law of free fall is explored herein. When stepping into general relativity, we report how the geodesic free fall into a black hole was the subject of an intense debate again centered on coordinate choice. Later, we describe how the infalling mass and the emitted gravitational radiation affect the free fall motion of a body. The general relativistic self-force might be dealt with to perfectly fit into a geodesic conception of motion. Then, embracing quantum mechanics, real black holes are not classical static objects any longer. Free fall has to handle the Hawking radiation, and leads us to new perspectives on the varying mass of the evaporating black hole and on the varying energy of the falling mass. Along the paper, we also estimate our findings for ordinary masses being dropped from a Galilean or Einsteinian Pisa-like tower with respect to the current state of the art drawn from precise measurements in ground and space laboratories, and to the constraints posed by quantum measurements. Appendix A describes how education physics and high impact factor journals discuss the free fall. Finally, case studies conducted on undergraduate students and teachers are reviewed.

We apply our method of indirect integration, described in Part I, at fourth order, to the radial fall affected by the self-force (SF). The Mode-Sum regularization is performed in the Regge–Wheeler gauge using the equivalence with the harmonic gauge for this orbit. We consider also the motion subjected to a self-consistent and iterative correction determined by the SF through osculating stretches of geodesics. The convergence of the results confirms the validity of the integration method. This work complements and justifies the analysis and the results appeared in [Int. J. Geom. Meth. Mod. Phys.11 (2014) 1450090].

The self-interaction for a static scalar charge in the space-time of extreme charged anti-dilatonic wormhole is calculated. We assume that the scalar charge is the source of massless scalar field with minimal coupling of the scalar field to the curvature of spacetime.

The self-energy and self-force for particles with electric and scalar charges at rest in the space-time of massless and massive wormholes are considered. The particle with electric charge is always attracted to wormhole throat for arbitrary profile of the throat. The self-force for scalar particle shows different behavior depending on the non-minimal coupling. The self-force for massive scalar field is localized close to the throat of the wormhole.

We establish the jump conditions for the wavefunction and its derivatives through the formal solutions of the wave equation. These conditions respond to the requirement of continuity of the perturbations at the position of the particle and they are given for any mode at first order. Using these jump conditions, we then propose a new method for computing the radiated waveform without direct integration of the source term. We consider this approach potentially applicable to generic orbits.

In a recent work, we presented the first application of the Poisson-Wiseman-Anderson method of “matched expansions” to compute the self-force acting on a point particle moving in a curved spacetime. The method employs two expansions for the Green function which are respectively valid in the “quasilocal” and “distant past” regimes, and which may be matched together within the normal neighbourhood. In this article, we introduce the method of matched expansions and discuss transport equation methods for the calculation of the Green function in the quasilocal region. These methods allow the Green function to be evaluated throughout the normal neighborhood and are also relevant to a broad range of problems from radiation reaction to quantum field theory in curved spacetime and quantum gravity.

We introduce a new time-domain method for computing the self-force acting on a scalar particle in a Schwarzschild geometry. The principal feature of our method consists in the division of the spatial domain into several subdomains and locating the particle at the interface betweem two them. In this way, we avoid the need of resolving a small length scale associated with the presence of a particle in the computational domain and, at the same time, we avoid numerical problems due to the low differentiability of solutions of equations with point-like singular behaviour.

We present the first successful application of the method of Matched Expansions for the calculation of the self-force on a point particle in a curved spacetime. We investigate the case of a scalar charge in the Nariai spacetime, which serves as a toy model for a point mass moving in the Schwarzschild black hole background. We discuss the singularity structure of the Green function beyond the normal neighbourhood and the interesting effect of caustics on null wave propagation.

We present results from calculations of the orbital evolution in eccentric binaries of nonrotating black holes with extreme mass-ratios. Our inspiral model is based on the method of osculating geodesics, and is the first to incorporate the full gravitational self-force (GSF) effect, including conservative corrections. The GSF information is encapsulated in an analytic interpolation formula based on numerical GSF data for over a thousand sample geodesic orbits. We assess the importance of including conservative GSF corrections in waveform models for gravitational-wave searches.