Results 31 to 40 of about 125 (115)

On a rigidity result for Kolmogorov-type operators

Bruno Pini Mathematical Analysis Seminar
Let D be a bounded open subset of ℝN and let z0 be a point of D. Assume that the Newtonian potential of D is proportional outside D to the potential of a mass concentrated at z0. Then D is a Euclidean ball centred at z0. This theorem, proved by Aharonov,
Alessia E. Kogoj
doaj   +1 more source

CR$CR$ analysis via local uniform completion, a sharp maximum modulus principle and holomorphic extension

Journal of the London Mathematical Society, Volume 111, Issue 5, May 2025.
Abstract Using iterated uniform local completion, we introduce a notion of continuous CR$CR$ functions on locally closed subsets of reduced complex spaces, generalising both holomorphic functions and CR$CR$ functions on CR$CR$ submanifolds. Under additional assumptions of set‐theoretical weak pseudo‐concavity, we prove optimal maximum modulus ...
Mauro Nacinovich, Egmont Porten
wiley   +1 more source

Parameter Estimation for Fractional Diffusion Process with Discrete Observations

Journal of Function Spaces, Volume 2019, Issue 1, 2019., 2019
This paper deals with the problem of estimating the parameters for fractional diffusion process from discrete observations when the Hurst parameter H is unknown. With combination of several methods, such as the Donsker type approximate formula of fractional Brownian motion, quadratic variation method, and the maximum likelihood approach, we give the ...
Yuxia Su, Yutian Wang, Yong H. Wu
wiley   +1 more source

Parameter Estimation of a Partially Observed Hypoelliptic Stochastic Linear System

Mathematics
In this article, we address the problem of the parameter estimation of a partially observed linear hypoelliptic stochastic system in continuous time, a relevant problem in various fields, including mechanical and structural engineering.
Nilton O. B. Ávido, Paula Milheiro-Oliveira   +1 more
doaj   +1 more source

Hypoellipticity for infinitely degenerate quasilinear equations and the dirichlet problem [PDF]

Journal d'Analyse Mathématique, 2013
45 pages, 4 ...
Rios, Cristian, Sawyer, Eric T., Wheeden, Richard L.   +2 more
openaire   +3 more sources

On linearization and uniqueness of preduals

Mathematische Nachrichten, Volume 298, Issue 3, Page 955-975, March 2025.
Abstract We study strong linearizations and the uniqueness of preduals of locally convex Hausdorff spaces of scalar‐valued functions. Strong linearizations are special preduals. A locally convex Hausdorff space F(Ω)$\mathcal {F}(\Omega)$ of scalar‐valued functions on a nonempty set Ω$\Omega$ is said to admit a strong linearization if there are a ...
Karsten Kruse
wiley   +1 more source

A comparison principle for nonlinear heat Rockland operators on graded groups

Bulletin of the London Mathematical Society, Volume 50, Issue 5, Page 753-758, October 2018., 2018
Abstract In this note we show a comparison principle for nonlinear heat Rockland operators on graded groups. We give a simple proof for it using purely algebraic relations. As an application of the established comparison principle we prove the global in t‐boundedness of solutions for a class of nonlinear equations for the heat p‐sub‐Laplacian on ...
Michael Ruzhansky, Durvudkhan Suragan
wiley   +1 more source

Compactness in kinetic transport equations and hypoellipticity

Journal of Functional Analysis, 2011
The authors establish improved hypoelliptic estimates on the solutions of kinetic transport equations, using a suitable decomposition of the phase space. It is shown that the relative compactness in all variables of a bounded family of nonnegative functions \(f_\lambda(x,v)\in L^1\) satisfying some appropriate transport relation \[ v\cdot \nabla_x f_ ...
Arsénio, Diogo, Saint-Raymond, Laure
openaire   +1 more source

Bounds on Riesz Means of the Eigenvalues for Baouendi–Grushin Type Operators

International Journal of Mathematics and Mathematical Sciences, Volume 2025, Issue 1, 2025.
The aim of this paper is to consider spectral inequalities of a class of Baouendi–Grushin type operators in cylinders. Such operators are hypoelliptic and we obtain non‐Weyl type inequalities depending on the rate of the degeneracy. We also give an example where all eigenvalues and eigenfunctions are computed explicitly.
Alaa Aljahili, Ari Laptev, Shikha Binwal
wiley   +1 more source

Disuguaglianze di Harnack alla frontiera per equazioni di Kolmogorov

Bruno Pini Mathematical Analysis Seminar, 2011
We describe some recent results on the boundary regularity for hypoelliptic Kolmogorov equations. We prove boundary Harnack inequalities of the positive solutions to Kolmogorov equations vanishing on some relatively open subset of the boundary ...
Sergio Polidoro
doaj