New Directions in Conventional and Ambitwistor String Theories

The goal of the workshop is to foster interaction between researchers working on the S-matrices of conventional strings and on ambitwistor strings.  The workshop will exploit synergies between the two frameworks and identify the current key questions in the fields and areas that can benefit from collaboration. The program of the workshop will be tailored to questions and problems raised by the participants in the run-up to the event. The goal is to spend most of the time on collaborative discussions in order to exchange expertise and to attempt to resolve questions during the workshop. A list of such problems can be found below and this will be extended by the participants in the run-up to the meeting. To obtain ambitwistor integrands and Bern-Carrasco-Johansson (BCJ) numerators for multiloop amplitudes and to connect with superstring worldsheet correlators. To develop fully nonlinear approaches by working on curved backgrounds both for application to AdS/CFT and to problems in perturbative gravity and gauge theory on nontrivial backgrounds. To understand the twistor and ambitwistor geometry underpinning both conventional and ambitwistor strings including the geometry of soft limits infrared structure and its links with formulations at null infinity. To explore mathematical structures behind the integrals of conventional and ambitwistor strings (positive geometries and canonical forms twisted (co)-cycle etc.)