Abstract
We define the rigidity of a Feynman integral to be the smallest dimension over which it is nonpolylogarithmic. We prove that massless Feynman integrals in four dimensions have a rigidity bounded by 2(L-1) at L loops provided they are in the class that we call marginal: those with (L+1)D/2 propagators in (even) D dimensions. We show that marginal Feynman integrals in D dimensions generically involve Calabi-Yau geometries, and we give examples of finite four-dimensional Feynman integrals in massless φ4 theory that saturate our predicted bound in rigidity at all loop orders.
Original language | English |
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Article number | 031601 |
Journal | Physical Review Letters |
Volume | 122 |
Issue number | 3 |
Number of pages | 7 |
ISSN | 0031-9007 |
DOIs | |
Publication status | Published - 24 Jan 2019 |