Related papers: High-energy String Scatterings of Compactified Ope…
Scattering amplitudes for discrete states in 2D string theory are considered. Pole divergences of tree-level amplitudes are extracted and residues are interpreted as renormalized amplitudes for discrete states. An effective Lagrangian…
In this thesis, we study the properties of String theory amplitudes within the framework of Intersection Theory (IT) for twisted (co)homology, which, as recently proposed, offered a novel approach to analyze relations between scattering…
This note illustrates the possibility in simple loaded string models of trapping most of the system energy in a single degree of freedom for very long times, demonstrating in particular that the robustness of the trapping is enhanced by…
We study some conditions for the hierarchy $m_{3/2} << M_P$ to occur naturally in a generic effective supergravity theory. Absence of fine-tuning and perturbative calculability require that the effective potential has a sliding gravitino…
We provide a qualitative review of flux compactifications of string theory, focusing on broad physical implications and statistical methods of analysis.
Compactified string theories give rise to discrete symmetries which are essential if they are to provide a realistic low energy theory. We find that in a class of four dimensional string theories these symmetries are constrained by similar…
We propose a candidate Compton amplitude which is valid for any (integer) quantum spin and free from any spurious poles. We consider the cases of electromagnetism and gravity. We obtain such amplitudes by calculating the corresponding ones…
The non-compact CFT of a class of NS-supported pp-wave backgrounds is solved exactly. The associated tree-level covariant string scattering amplitudes are calculated. The S-matrix elements are well-defined, dual but not analytic as a…
1. Preliminaries. 2. Heterotic string and motivations for large volume compactifications; 2.1 Gauge coupling unification; 2.2 Supersymmetry breaking by compactification. 3. M-theory on S^1/Z_2 \times Calabi-Yau. 4. Type I/I' string theory…
We calculate couplings of arbitrary order from correlation functions among twisted strings, using conformal field theory. Twisted strings arise in heterotic string compactified on orbifolds yielding matter fields in the low energy limit. We…
We derive a local, crossing symmetric dispersion relation (CSDR) for 2-2 scattering amplitudes with a parametric ambiguity motivated by string theory. Various limits of the parameter lead to the fixed-t, fixed-s, and other known CSDRs. We…
We express one-loop string amplitudes involving both open and closed strings as sum over pure open string amplitudes. These findings generalize the analogous tree-level result to higher loops and extend the tree-level observation that in…
We derive fully covariant expressions for all two-point scattering amplitudes of two massless closed strings from a Dirichlet $p$-brane. This construction relies on the observation that there is a simple relation between these D-brane…
We study the entanglement entropy between the two outgoing particles in an elastic scattering process. It is formulated within an S-matrix formalism using the partial wave expansion of two-body states, which plays a significant role in our…
In the background of several holographic confining backgrounds, we present the connections between the behaviors of string scattering amplitudes and mutual information. We lay down the analogies between the logarithmic branch cut behavior…
The low-energy effective theory description of a confining theory, such as QCD, is constructed including local interactions between hadrons organized in a derivative expansion. This kind of approach also applies more generically to theories…
The renormalisation of NN scattering in theories with zero-range interactions is examined using a cut-off regularisation where the cut-off is taken to infinity, dimensional regularisation (DR) with minimal subtraction, and DR with…
This paper discusses the gravitational scattering of a straight, infinitely long test cosmic string by a black hole. We present numerical results that probe the two-dimensional parameter space of impact parameter and initial velocity and…
A brief historical overview of various modern approaches to the problem under consideration is given. It includes existing models based on a sum of different terms of the scattering amplitude with different signs and Regge-eikonal models…
We present scattering of stringy states of closed bosonic string compactified on d-dimensional torus. We focus our attention on scattering of moduli and gauge bosons. These states appear when massless excitations such as graviton and…