Related papers: Gravitational effects in ultrahigh-energy string s…
We study acceleration of current-carrying string loops governed by the presence of an outer tension barrier and an inner angular momentum barrier in the field of Schwarzschild-de Sitter black holes. We restrict attention to the axisymmetric…
We revisit possible glimpses of black-hole formation by looking at ultra-planckian string-string collisions at very high final-state multiplicity. We compare, in particular, previous results using the optical theorem, the resummation of…
We study the system formed by a gaz of black holes and strings within a microcanonical formulation. We derive the microcanonical content of the system: entropy, equation of state, number of components N, temperature T and specific heat. The…
We construct, for the first time, the time-domain gravitational wave strain waveform from the collapse of a strongly gravitating Abelian Higgs cosmic string loop in full general relativity. We show that the strain exhibits a large memory…
We study gravitational absorption effects using effective on-shell scattering amplitudes. We develop an in-in probability-based framework involving plane- and partial-wave coherent states for the incoming wave to describe the interaction of…
The gravitational interaction of an infinitely long cosmic string with a Schwarzschild black hole is studied. We consider a straight string that is initially at a great distance and moving at some initial velocity v (0 < v < c) towards the…
I solve the equations of the low-energy limit of string theory to obtain a solution corresponding to a microcanonical ensemble of highly-excited superstrings. This ``Superball of Strings'' is a static, spherically symmetric ``fuzzball'' of…
The gravitational wave strain emitted by a perturbed black hole (BH) ringing down is typically modeled analytically using first-order BH perturbation theory. In this Letter we show that second-order effects are necessary for modeling…
A general description of string excitations in stationary spacetimes is developed. If a stationary string passes through the ergosphere of a 4-dimensional black hole, its world-sheet describes a 2-dimensional black (or white) hole with…
We generalize the effective point particle approach to black hole dynamics to include spin. In this approach dissipative effects are captured by degrees of freedom localized on the wordline. The absorptive properties of the black hole are…
Neutrinos undergoing stochastic perturbations as they propagate experience decoherence, damping neutrino oscillations over distance. Such perturbations may result from fluctuations in space-time itself if gravity is a quantum force,…
Multiple gauge theories predict the presence of cosmic strings with different mass densities $G\mu/c^2$. We derive an equation governing the perturbations of a rotating black hole pierced by a straight, infinitely long cosmic string along…
The explanation of black hole entropy as statistical entropy is one of the big successes of string theory. In this article we review recent progress in this subject, focussing on understanding quantum effects on black hole entropy.…
Dark matter effects may be attributed to interactions between the Machian strings connecting every pair of elementary particles in the observable Universe. A simple model for the interaction between Machian strings is proposed. In the early…
We study the pair creation of point-particles and strings in a time-dependent, weak gravitational field. We find that, for massive string states, there are surprising and significant differences between the string and point-particle…
In contrast to the common wisdom, we discover that, instead of the exponential fall-off of the form factors with Regge-pole structure, the high-energy scattering amplitudes of string scattered from Domain-wall behave as power-law with…
Ultralight degrees of freedom coupled to matter lead to resonances, which can be excited when the Compton wavelength of the field equals a dynamical scale in the problem. For binaries composed of a star orbiting a supermassive black hole,…
The gravitational field of two-body system, a high energetic particle and a massive particle at rest, is studied in the linearized Einstein gravity. The ultrarelativistic particle yields a plane-fronted gravitational shockwave which…
We study the stability of superconducting strings in a U(1)_{local} x U(1)_{global} model coupled via a gauge field interaction term to U(1) Abelian-Higgs strings. The effect of the interaction on current stability is numerically…
The scattering of a charged fermion from an electroweak string is studied. Owing to an amplification of the wave function at the core radius, the cross sections for helicity flip processes can be largely enhanced. For $0 <\sin^2 \theta_w <…