Related papers: Gravitational Properties of Quantum Bosonic String…
If cosmic strings are formed in the early universe, their associated loops emit gravitational waves during the whole cosmic history and contribute to the stochastic gravitational wave background at all frequencies. We provide a new estimate…
The bosonic string in D dimensional Minkowski space-time is quantized in static gauge. It is shown that the system can be described by D-1 massless free fields constrained on the surface L_m = 0, for m \neq 0, where L_m are the generators…
We study the effect of internal space rotation on the gravitational properties of infinite straight and stationary cosmic string. From the approximate solution of Einsten equations for the spinning Q-lump string we obtain long range…
We revisit the construction of the tensionless limit of closed bosonic string theory in the covariant formulation in the light of Galilean conformal symmetry that rises as the residual gauge symmetry on the tensionless worldsheet. We relate…
In this short paper we investigate quantum gravitational effects on Einstein's equations using effective field theory techniques. We consider the leading order quantum gravitational correction to the wave equation. Besides the usual…
Appearance of cosmic strings in the early Universe is a common manifestation of new physics typically linked to some high energy scale. In this paper, we discuss a different situation, where a model underlying cosmic string formation is…
We do a complete calculation of the stochastic gravitational wave background to be expected from cosmic strings. We start from a population of string loops taken from simulations, smooth these by Lorentzian convolution as a model of…
We study the scattering of a massless and neutral test particle in the gravitational field of a body (the string star) made of a large number of scalar states of the superstring. We consider two cases, the one in which these states are…
A quantitatively verifiable expression for the Gravitational Constant is derived in terms of quantum mechanical quantities. This derivation appears to be possible by selecting a suitable physical process in which the transformation of the…
A gravitational theory involving a vector field $\chi^{\mu}$, whose zero component has the properties of a dynamical time, is studied. The variation of the action with respect to $\chi^{\mu}$ gives the covariant conservation of an energy…
We compute the stochastic gravitational wave background generated by cosmic superstrings using a semi-analytical velocity-dependent model to describe their dynamics. We show that heavier string types may leave distinctive signatures on the…
We examine the spectrum of gravitational radiation emitted by a network of cosmic strings, with emphasis on the observational constraints and the opportunities for detection. The analysis improves over past work, as we use a…
It is argued that quantum states of geometry, like those of particles, should be coherent on light cones of any size. An exact classical solution, the gravitational shock wave of a relativistic point particle, is used to estimate…
A simple model for the formation of a straight cosmic string, wiggly or unperturbed is considered. The gravitational field of such string is computed in the linear approximation. The vacuum expectation value of the stress tensor of a…
We investigate classical dynamics of the bosonic string in the background metric, antisymmetric and dilaton fields. We use canonical methods to find Hamiltonian in terms of energy-momentum tensor components. The later are secondary…
We derive general formulae for computing the average spectrum for Bosonic or Fermionic massless emission from generic or particular sets of closed superstring quantum states, among the many occurring at a given large value of the number…
It is well-known that some physical effects may arise in the spacetime of a straigth cosmic string due to its global conic properties. Among these effects, the vacuum polarization effect has been extensively studied in the litterature. In…
Cosmic strings are predicted in many extensions of the Standard Model and constitute a plausible source of gravitational waves (GWs) from the early Universe. In a previous article arXiv:2405.10937v2, we pointed out that the GW spectrum from…
A spectrum of relic stochastic gravitational radiation, strongly tilted towards high frequencies, and characterized by two basic parameters is shown to emerge in a class of string theory models. We estimate the required sensitivity for…
We show that the noncritical string field theory developed from two-dimensional quantum gravity in the framework of causal dynamical triangulations can be viewed as arising through a stochastic quantization. This requires that the proper…