Conveners
Parallel Session Thursday: Strings / Mathematical Physics III
- Anne Spiering (Trinity College Dublin)
The Amplituhedron provides, via geometric means, the all-loop integrand of scattering amplitudes in maximally supersymmetric Yang-Mills theory. Unfortunately, dimensional regularization, used conventionally for integration, breaks the beautiful geometric picture. This motivates us to propose a `deformed' Amplituhedron. Focusing on the four-particle amplitude, we introduce two deformation...
We provide evidence through two loops, that rational letters of polylogarithmic Feynman integrals are captured by the Landau equations, when the latter are recast as a polynomial of the kinematic variables of the integral, known as the principal $A$-determinant. Focusing on one loop, we further show that all square-root letters may also be obtained, by re-factorizing the principal...
We consider the ensemble average of two dimensional symmetric product orbifold CFTs $\text{Sym}^N(\mathbb{T}^D)$ over the Narain moduli space. We argue for a bulk dual given by $N$ copies of an abelian Chern-Simons theory coupled to topological gravity, endowed with a discrete gauge symmetry exchanging the $N$ copies. As a check of this proposal, we calculate the ensemble average of various...
Celestial holography is a candidate for flat space holography. Scattering amplitudes of massless particles in the bulk four dimensional Minkowski spacetime can be mapped to correlators in a putative two dimensional conformal field theory living on the celestial sphere via Mellin transform.
In 1806.05688 string tree level amplitudes have been cast into their celestial form. In it, the...
In this work, we have exclusively employed linear stability analysis at ultra-high boost on two well-known stable-causal theories - second-order MIS and first-order BDNK, to identify the region of parameter space over which they are frame-invariantly stable and obey causal signal propagation. It has been shown that at near-luminal boost, stability criteria alone can provide the causality...
The structure of tree-level string amplitudes has been illuminated by the use of Intersection Theory. In this talk we explore extensions of the Intersection-Theory approach to one-loop string amplitudes, based on the twisted cohomology of so-called Riemann-Wirtinger integrals in the Mathematics literature. In the same way as KLT relations reduce tree-level closed string amplitudes to squares...
