Seminar series
Date
Wed, 25 Nov 2026
Time
11:00 -
13:00
Location
L4
Speaker
Salvador Esquivel
Organisation
(Mathematical Institute University of Oxford)
We extend the construction of BPHZ renormalised models in regularity structures via the spectral gap inequality to the fractional heat operator. Its Green’s function fails to be smooth across the entire time-zero hyperplane, violating the classical assumption that kernels are smooth away from the origin. The proof requires a delicate balance between the gain in regularity provided by the spectral gap approach and the limited spatial decay of the kernel.
Joint work with L. Broux and R. Steele.