J. P. G. Ramos

collaborators

3 papers

math.CA2023

Stability of the Faber-Krahn inequality for the Short-time Fourier Transform

Jaime Gómez, André Guerra, João P. G. Ramos +1

We prove a sharp quantitative version of the Faber--Krahn inequality for the short-time Fourier transform (STFT). To do so, we consider a deficit $δ (f; Ω)$ which measures by how muc…

math.MG2023

A quantitative stability result for the sphere packing problem in dimensions 8 and 24

Károly J. Böröczky, Danylo Radchenko, João P. G. Ramos

We prove explicit stability estimates for the sphere packing problem in dimensions 8 and 24, showing that, in the lattice case, if a lattice is $\sim ε$ close to satisfyi…

math.FA2022

A Faber-Krahn inequality for wavelet transforms

João P. G. Ramos, Paolo Tilli

For some special window functions $ψ_{β} \in H^{2} (C^{+}),$ we prove that, over all sets $Δ \subset C^{+}$ of fixed hyperbolic measure $ν (Δ),$ the ones over which the Wave…