TY - JOUR
T1 - Cancellations beyond finiteness in N=8 supergravity at three loops
AU - Bern, Z.
AU - Carrasco, John Joseph
AU - Dixon, L. J.
AU - Johansson, H.
AU - Kosower, D. A.
AU - Roiban, R.
PY - 2007/4/19
Y1 - 2007/4/19
N2 - We construct the three-loop four-point amplitude of N=8 supergravity using the unitarity method. The amplitude is ultraviolet finite in four dimensions. Novel cancellations, not predicted by traditional superspace power-counting arguments, render its degree of divergence in D dimensions no worse than that of N=4 super-Yang-Mills theory-a finite theory in four dimensions. Similar cancellations can be identified at all loop orders in certain unitarity cuts, suggesting that N=8 supergravity may be a perturbatively finite theory of quantum gravity.
AB - We construct the three-loop four-point amplitude of N=8 supergravity using the unitarity method. The amplitude is ultraviolet finite in four dimensions. Novel cancellations, not predicted by traditional superspace power-counting arguments, render its degree of divergence in D dimensions no worse than that of N=4 super-Yang-Mills theory-a finite theory in four dimensions. Similar cancellations can be identified at all loop orders in certain unitarity cuts, suggesting that N=8 supergravity may be a perturbatively finite theory of quantum gravity.
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U2 - 10.1103/PhysRevLett.98.161303
DO - 10.1103/PhysRevLett.98.161303
M3 - Article
C2 - 17501410
AN - SCOPUS:34247354052
SN - 0031-9007
VL - 98
JO - Physical review letters
JF - Physical review letters
IS - 16
M1 - 161303
ER -