相关论文: Massive Spin-5/2 Fields Coupled to Gravity: Tree-L…

We find the complete set of conditions satisfied by the forward $2\to2$ scattering amplitude in unitarity and causal theories. These are based on an infinite set of energy dependent quantities -- the arcs -- which are dispersively expressed…

The non-minimal coupling of scalar fields to gravity has been claimed to violate energy conditions, leading to exotic phenomena such as traversable wormholes, even in classical theories. In this work we adopt the view that the non-minimal…

The spin-4/3 fractional superstring is characterized by a chiral algebra involving a spin-4/3 current on the world-sheet in addition to the energy-momentum tensor. These currents generate physical state conditions on the fractional…

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…

We show that gravitational theories with a nonminimal coupling (NMC) to the matter fields lead to a violation of Etherington's distance-duality relation, which relates the luminosity and angular diameter distances. We derive constraints on…

Tree-level scattering amplitudes in Yang-Mills theory satisfy a recursion relation due to Berends and Giele which yields e.g. the famous Parke-Taylor formula for MHV amplitudes. We show that the origin of this recursion relation becomes…

We present lattice results for the ground state energy of a spin-1/2 fermion system in the unitary limit, where the effective range of the interaction is zero and the scattering length is infinite. We compute the ground state energy for a…

String theory suggests the existence of gravitational-strength scalar fields ("dilaton" and "moduli") whose couplings to matter violate the equivalence principle. This provides a new motivation for high-precision clock experiments, as well…

We give examples of minimal extensions of the simplest SU(5) SUSY-GUT in which all squarks and sleptons of a family have different tree level masses at the unification scale. This phenomenon is general; it occurs when the quarks and leptons…

The asymptotic behavior of the scattering amplitude for two scalar particles at high energies with fixed momentum transfers is studied. The study is done within the effective theory of quantum gravity based on quasi-potential equation. By…

A unified field theory of all known basic forces and elementary particles is built based on the postulates of gauge invariance and coordinate independence along with general conformal scaling symmetry. The hyper-spin charge of a unified…

Using on-shell gauge invariant formulation of relativistic dynamics we study interaction vertices for a massive spin 5/2 Dirac field propagating in (A)dS space of dimension greater than or equal to four. Gravitational interaction vertex for…

In the past, Kundu et al. and Chakraborty et al. used extra scalar fields to cancel the quadratic divergences in the Higgs mass squared and they determined the mass of the required scalar field. In this work, a spin-3/2 particle has been…

We study the relationship between the strength of fifth forces and the origin of scale breaking in the Standard Model (SM) of particle physics. We start with a light scalar field that is conformally coupled to a toy SM matter sector through…

We consider effective theories with massive fields that have spins larger than or equal to two. We conjecture a universal cutoff scale on any such theory that depends on the lightest mass of such fields. This cutoff corresponds to the mass…

KLT relations almost factorize closed string amplitudes on $S_2$ by two open string tree amplitudes which correspond to the left- and the right- moving sectors. In this paper, we investigate string amplitudes on $D_2$ and $RP_2$. We find…

In five dimensional models of Higgsless electroweak symmetry breaking, tree level unitarity in gauge boson scattering is restored by the exchange of gauge boson Kaluza-Klein modes instead of a Higgs boson. Unitarity of scattering amplitudes…

Amplitude methods have proven to be a promising technique to perform Post-Minkowskian calculations used as inputs to construct gravitational waveforms. In this paper, we show how these methods can be extended beyond the standard…

We study the transmission of supersymmetry breaking via gravitational interactions in a five-dimensional brane-world compactified on $S^1/Z_2$. We assume that chiral matter and gauge fields are confined at the orbifold fixed points, where…

The possibility to achieve unification at the string scale in the context of the simplest supersymmetric grand unified theory is investigated. We find conservative upper bounds on the superpartner masses consistent with the unification of…