activity
20182025
most citedSmoothing Properties of Fractional Ornstein-Uhlenbeck Semigroups and Null-Controllability

18 citations · 26 across the 13 of their papers we have counts for

collaborators

14 papers

math.AP2025

Observability estimates for the Schrödinger equation on the equilateral triangle

Paul Alphonse, David Lafontaine

We prove observability estimates for the Schrödinger equation posed on the equilateral triangle in the plane, under both Neumann and Dirichlet boundary conditions. No geometric con…

math.AP2024★ 1 cited

Unique continuation estimates for Baouendi--Grushin equations on cylinders

Paul Alphonse, Albrecht Seelmann

We prove time-pointwise quantitative unique continuation estimates for the evolution operators associated to (fractional powers of) the Baouendi--Grushin operators on the cylinder…

math.AP2023

Null-controllability for weakly dissipative heat-like equations

Paul Alphonse, Armand Koenig

We study the null-controllability properties of heat-like equations posed on the whole Euclidean space . These evolution equations are associated with Fourier multipli…

math.AP2022

Null-controllability for weakly dissipative heat-like equations

Armand Koenig, Paul Alphonse

We study the null-controllability properties of heat-like equations posed on the whole Euclidean space . These evolution equations are associated with Fourier multipli…

math.AP2022★ 2 cited

Quantitative spectral inequalities for the anisotropic Shubin operators and applications to null-controllability

Paul Alphonse, Albrecht Seelmann

We prove quantitative spectral inequalities for the (anisotropic) Shubin operators on the whole Euclidean space, thus relating for functions from spectral subspaces associated to f…

math.AP2022

Approximate null-controllability with uniform cost for the hypoelliptic Ornstein-Uhlenbeck equations

Paul Alphonse, Jérémy Martin

We prove that the approximate null-controllability with uniform cost of the hypoelliptic Ornstein-Uhlenbeck equations posed on is characterized by an integral thickne…

math.AP2021

Gains of integrability and local smoothing effects for quadratic evolution equations

Paul Alphonse, Joackim Bernier

We characterize geometrically the semigroups generated by non-selfadjoint quadratic differential operators enjoying local smoothing effects and providing ga…

math.AP2021

Stabilization and approximate null-controllability for a large class of diffusive equations from thick control supports

Paul Alphonse, Jérémy Martin

We prove that the thickness property is a necessary and sufficient geometric condition that ensures the (rapid) stabilization or the approximate null-controllability with uniform c…

math.AP2020★ 4 cited

Null-controllability of evolution equations associated with fractional Shubin operators through quantitative Agmon estimates

Paul Alphonse

We consider the anisotropic Shubin operators acting on the space , with some positive integers. We provide sharp quantit…

math.AP2020

Hypoelliptic estimates for linear transport operators

Paul Alphonse

We aim at understanding how the non-commutation phenomena between a linear transport operator and a fractional diffusion allow the transport operator to satisfy hypoelliptic estima…

math.AP2020

Description of the smoothing effects of semigroups generated by fractional Ornstein-Uhlenbeck operators and subelliptic estimates

Paul Alphonse

We study semigroups generated by general fractional Ornstein-Uhlenbeck operators acting on . We characterize geometrically the partial Gevrey-type smoothing proper…

math.AP2019★ 1 cited

Polar decomposition of semigroups generated by non-selfadjoint quadratic differential operators and regularizing effects

Paul Alphonse, Joackim Bernier

We characterize geometrically the regularizing effects of the semigroups generated by accretive non-selfadjoint quadratic differential operators. As a byproduct, we establish the s…

math.AP2019

Quadratic differential equations : partial Gelfand-Shilov smoothing effect and null-controllability

Paul Alphonse

We study the partial Gelfand-Shilov regularizing effect and the exponential decay for the solutions to evolution equations associated to a class of accretive non-selfadjoint quadra…

math.AP2018★ 18 cited

Smoothing Properties of Fractional Ornstein-Uhlenbeck Semigroups and Null-Controllability

Paul Alphonse, Joackim Bernier

We study fractional hypoelliptic Ornstein-Uhlenbeck operators acting on satisfying the Kalman rank condition. We prove that the semigroups generated by these op…