Related papers: String Pair Production in a Time-Dependent Gravita…
We study the instantons describing the production of particles at the ends of codimension-one objects (strings and struts) in $(2+1)$-dimensional Minkowski and de Sitter spaces. A Minkowskian background allows only for systems with…
We derive the pair-production probability in a constant electric field in Rindler coordinates in a quasi-classical approximation. Our result is different from the pair-production probability in an inertial frame (Schwinger formula). In…
Particle production through ultra-strong electric fields is a well-studied research field. Nevertheless, despite repeated attempts to relate the production rate within the field to the formation time of a particle, the latter is still…
We argue that the light particles in string theory obey an effective quantum mechanics modified by the inclusion of a quantum-gravitational friction term, induced by unavoidable couplings to unobserved massive string states in the…
We study the space-time invariances of the bosonic relativistic particle and bosonic relativistic string using general formulations obtained by incorporating the Hamiltonian constraints into the formalism. We point out that massless…
We compute spectra of particles produced during a dilaton-driven kinetic inflation phase within string cosmology models. The resulting spectra depend on the parameters of the model and on the type of particle and are quite varied, some…
I consider a truncation of low-energy string theory which contains two $U(1)$ gauge fields. After making some general comments on the theory, I describe a previously-obtained instanton for the pair creation of black holes when both gauge…
In this thesis we are interested in the study of the gravitational properties of quantum bosonic strings. We start by computing the quantum energy-momentum tensor ${\hat T}^{\mu\nu}(x)$ for strings in Minkowski space-time. We perform the…
We extend the effective field theory (EFT) formalism for gravitational radiation from a binary system of compact objects to the case of extended objects. In particular, we study the EFT for a binary system consisting of two infinitely-long…
As a follow up of the seminal work by Guiot, Borquez, Deur, and Werner on "Graviballs and Dark Matter", we explicitly show that contrary to Einstein's gravity, in string theory, local and nonlocal higher derivative theories, as well as…
We study the gravitational production of heavy X-particles of mass of the order of the inflaton mass, produced after the end of inflation. We find that, in the presence of a derivative coupling of the inflaton field or of the X-field to the…
We propose a mechanism to have a smooth transition from a pre-Big Bang phase to a standard cosmological phase. Such transition is driven by gravitational production of heavy massive string states that backreact on the geometry to stop the…
This elementary introduction to string field theory highlights the features and the limitations of this approach to quantum gravity as it is currently understood. String field theory is a formulation of string theory as a field theory in…
Gravitational and massless particle radiation of straight cosmic strings with finite thickness is studied analytically. It is found that the non-linear interaction of the radiation fields emitted by a cosmic string with the ones of the…
The quantum vacuum is unstable under the influence of an external electric field and decays into pairs of charged particles, a process which is known as the Schwinger pair production. We propose and demonstrate that this electric field can…
We investigate entanglement generation between two pulses through the gravitational interaction in the framework of linearized quantum gravity. Different from the earlier suggestions that two massive particles can be entangled through the…
String theory, if it describes nature, is probably strongly coupled. As a result, one might despair of making any statements about the theory. In the framework of a set of clearly spelled out assumptions, we show that this is not…
In addition to being a prime candidate for a fundamental unified theory of all interactions in nature, string theory provides a natural setting to understand gauge field theories. This is linked to the concept of "D-branes": extended,…
We formulate the string field theory in zero-dimensional target space corresponding to the two-dimensional quantum gravity theory defined through Causal Dynamical Triangulations. This third quantization of the quantum gravity theory allows…
Strong enough electric field is predicted to spontaneously create electron-positron pairs in vacuum via Schwinger effect. A somewhat similar effect is predicted to occur in sufficiently strong inhomogeneous gravitational fields. However,…