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SUMMARY:Zihan Wang (Imperial College) - Energy of wrapped M2 branes at hig
 her loops
DTSTART:20260902T130000Z
DTEND:20260902T140000Z
DTSTAMP:20260910T165600Z
UID:indico-event-2205@indico.uu.se
DESCRIPTION:Speakers: Zihan Wang (Imperial College London)\n\nThe static-g
 auge Green–Schwarz strings and supermembranes are formally non-renormali
 zable. Some quantities may still be free of logarithmic UV divergences and
  thus be defined unambiguously. One example is the energy of an M2 brane w
 rapping one or two compact directions in a flat background. For an M2 bran
 e wrapped on a two-torus\, the one- and two-loop corrections are free of l
 ogarithmic UV divergences and are well defined using zeta-function regular
 ization. With periodic fermions\, the quantum corrections cancel\, as expe
 cted from supersymmetry\, whereas antiperiodic boundary conditions lead to
  non-trivial functions of the compactification radii involving modified Be
 ssel functions. In the string case\, the static-gauge loop expansion repro
 duces the expansion of the exact square-root spectrum. At three loops\, ho
 wever\, the membrane displays new structure: in addition to powers of the 
 one-loop zeta(3) coefficient\, the basketball diagram generates a new zeta
 (9) term. The leading large-N bubble diagrams can nevertheless be resummed
 : they give the quadratic equation and square-root energy for the string\,
  but a cubic equation for the membrane. We find that the bubble-graph part
  of the membrane energy does not vanish for any value of the radius R_{11}
 . We also generalize the two-loop analysis to an M2 brane in a flat eleven
 -dimensional “twisted” background that interpolates between periodic a
 nd antiperiodic fermion boundary conditions.\n\nhttps://indico.uu.se/event
 /2205/
LOCATION:92110 (Ångströmlaboratoriet)
URL:https://indico.uu.se/event/2205/
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