- Main
Ultraviolet Behavior of Supergravity Amplitudes
- Edison, Alex
- Advisor(s): Bern, Zvi
Abstract
In this manuscript, we detail three recent calculations
addressing the ultraviolet behavior of supersymmetric quantum
gravity. First, we revisit the classic calculation of the two-loop
pure gravity divergence. We argue that the $\frac{1}{\epsilon}$
divergence is regulator and duality dependent. In its place, we
propose that examining the running of the scaling parameter,
$\log \mu$, is a duality and regulator independent approach to
assessing gravity divergences in four dimensions. We explicitly
calculate the $\log \mu$ coefficient at two loops for gravity with
any particle content, explicitly verifying the divergences for pure
gravity, and the finiteness for supersymmetric gravities. Second,
we analyze fully-integrated $\NeqFour$ supergravity at one loop
using the double copy. We find that there are evanescent effects at
one loop that come directly from evanescent terms in
pure-Yang--Mills. Using this observation, we lay the groundwork for
deeper analysis of the $U(1)$ anomaly with respect to the observed
evanescent behavior. Finally, we tackle the long-standing question
of the critical dimension of $\NeqEight$ supergravity at five loops.
We construct an integrand using the generalized double copy, expand
the integrand in large loop momentum, and reduce the resulting
integrals using $\mathfrak{sl}(L)$ integration-by-parts relations.
This procedure yields a critical dimension of $d_c = 24/5$.
Main Content
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