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SUMMARY:Two-loop Integrands from the Riemann Sphere - Yvonne Geyer (Univer
 sity of Oxford)
DTSTART:20160630T103000Z
DTEND:20160630T113000Z
UID:TALK66623@talks.cam.ac.uk
CONTACT:INI IT
DESCRIPTION:<span> <span>Co-authors: Lionel Mason (University of Oxford)\,
   Ricardo Monteiro (CERN)\, Piotr Tourkine (University of  Cambridge) <br>
 </span></span> <span> <span> <br>Worldsheet formulations of quantum field 
 theories have had wide-ranging  impact on the study of scattering amplitud
 es. However\, the mathematical  framework becomes very challenging on the 
 higher-genus worldsheets required to  describe loop effects. I will descri
 be how\, in such worldsheet models based on  the scattering equations\, fo
 rmulae on higher-genus surfaces can be transformed  to ones on the Riemann
  sphere. My talk will focus on new developments at two loops for both supe
 rgravity and super Yang-Mills theory\, and briefly discuss a proposal for 
 the all-loop integrand.<br><br>Related Links <ul> <li><a target="_blank" r
 el="nofollow">http://arxiv.org/abs/1507.00321</a>   </li><li><a target="_b
 lank" rel="nofollow">http://arxiv.org/abs/1511.06315</a></li></ul></span><
 /span>
LOCATION:Seminar Room 1\, Newton Institute
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