Physics

We would like to discuss about soft gravitons. On the one hand, they enter in the soft theorems of gravity scattering which exhibit universal structures useful in the S-matrix program (e.g., 1404.4091, 1406.6987). On the other hand, they appear in...

The pure spinor formalism is an alternative description of the superstring which is manifestly spacetime supersymmetric and can be covariantly quantized. As a consequence, in recent years many superstring amplitudes which were impractical to...

Scattering amplitudes, in a wide variety of gauge theories, and independent of dimension and gauge group, have surprising kinematic structure which is currently only understood in terms of graphical rules relating the kinematic weights of graphs, in...

Motivated by black hole physics and holography, we study chaos, scrambling, and complexity by considering the entanglement properties of unitary operators. First, we develop a diagnostic of chaos by directly considering the time evolution of a...

Compactifying 6d N=(2,0) superconformal theories on Riemann surfaces yields 4d N=2 gauge theories. The sphere partition function of such a 4d theory is equal to a CFT correlator on the Riemann surface. The correspondence can be enriched by...

In the Friday seminar last week, Jennifer Lin talked about our joint work to characterize gravitational effective theories whose UV completions are dual to CFT’s on the boundary. I will discuss our attempt at its converse: how to characterize CFT’s...

In effective field theory, causality fixes the signs of certain interactions. I will describe how these Lorentzian constraints are encoded in the Euclidean theory, and use the conformal bootstrap to derive analogous causality constraints in CFT...

I will present results on how positivity properties of relative entropy in holographic CFT's give rise to energy conditions in asymptotically AdS spacetimes. This part will be a sequel to Nima Lashkari’s talk on 11/2. I will also comment on the...

During the first LHC long shutdown, the CMS collaboration finalised the study of the 8TeV data collected in 2012. Within the impressive amount of results produced, a few searches for new physics show a tension with the prediction from the Standard...

We will discuss the issue of UV completion in the context of weakly coupled theories. For concreteness, we will ask: is it possible to complete a low-energy 4-particle scattering amplitude into one which is well-behaved at high-energies, with only...