Related papers: BMS Supertranslations and Memory in Four and Highe…
Models with extra dimensions have attracted much interest recently because they may provide the solution for long standing problems in physics. One interesting and very attractive idea is that our visible universe is confined to a…
In higher-dimensional theories, a graviton propagating in the bulk can follow a shorter path, known as a shortcut, compared to a photon propagating in a four-dimensional spacetime. Thus by combining the observations of gravitational waves…
According to modern quantum physics, at the microlevel, the dimension of space-time is at least 11; we only observe 4 dimensions because the others are compactified: the size along each of the other dimensions is much smaller than the…
Gravitational memory, which describes the permanent shift in the strain after the passage of gravitational waves, is directly related to Weinberg's soft graviton theorems and the Bondi-Metzner-Sachs (BMS) symmetry group of asymptotically…
In this paper, we study $\mathcal{N} =1$ supersymmetric theories in four dimensions in presence of a boundary. We demonstrate that it is possible to preserve half the supersymmetry of the original theory by suitably modifying it in presence…
Null infinity in asymptotically flat spacetimes posses a rich mathematical structure; including the BMS group and the Bondi news tensor that allow one to study gravitational radiation rigorously. However, FLRW spacetimes are not…
Bodies coupled to electromagnetic or other long-range fields are subject to radiation reaction and other effects in which their own fields can influence their motion. Self-force phenomena such as these have been poorly understood for…
We consider a recent proposal to solve the cosmological constant problem within the context of brane world scenarios with infinite volume extra dimensions. In such theories bulk can be supersymmetric even if brane supersymmetry is…
The purpose of this dissertation is to examine the BMS symmetry group, which arises as the asymptotic symmetry group of four-dimensional asymptotically flat spacetimes at null infinity, and to uncover its relation to the Carroll group.…
The gravitational memory effects of Chern-Simons modified gravity are considered in the asymptotically flat spacetime. If the Chern-Simons scalar does not directly couple with the ordinary matter fields, there are also displacement, spin…
We use supertwistor space to construct scattering amplitudes of maximal superconformal theories in three and six dimensions. In both cases, the constraints of superconformal invariance and rationality imply that the three-point amplitude…
Gravitational-wave (GW) memory effects are constant changes in the GW strain and its time integrals, which are closely connected to changes in the charges that characterize asymptotically flat spacetimes. The first GW memory effect…
We obtain the non-perturbative effective potential for the dual five-dimensional N=4 strings in the context of finite-temperature regarded as a breaking of supersymmetry into four space-time dimensions. Using the properties of gauged N=4…
We propose that the UV/IR relation that underlies the AdS/CFT duality may provide a natural mechanism by which high energy supersymmetry can have large distance consequences. We motivate this idea via (a string realization of) the…
In theories with chiral couplings, one of the important consistency requirements is that of the cancellation of a gauge anomaly. In particular, this is one of the conditions imposed on the hypercharges in the Standard Model. However,…
Cosmological models with a de Sitter 3-brane embedded in a five-dimensional de Sitter spacetime (dS5) give rise to a finite 4D Planck mass similar to that in Randall-Sundrum (RS) brane-world models in AdS5 spacetime. Yet there arise a few…
The spin memory effect is a recently predicted relativistic phenomenon in asymptotically flat spacetimes that become nonradiative infinitely far in the past and future. Between these early and late times, the magnetic-parity part of the…
Four dimensional supergravities may be the right framework to describe particle physics at low energies. Its connection to the underlying string theory can be implemented through higher dimensional supergravities which bear special…
A class of supersymmetric (BPS saturated), static, spherically symmetric solutions of four-dimensional effective N=4 supersymmetric superstring vacua, which become massless at special points of moduli space, is studied in terms of the…
We study in detail the effect of quasicondensation. We show that this effect is strictly related to dimensionality of the system. It is present in one dimensional systems independently of interactions - exists in repulsive, attractive or in…