Results 11 to 20 of about 154 (95)
Analytic hypoellipticity of Keldysh operators [PDF]
Proceedings of the London Mathematical Society, Volume 123, Issue 5, Page 498-516, November 2021., 2021 Abstract We consider Keldysh‐type operators, P=x1Dx12+a(x)Dx1+Q(x,Dx′), x=(x1,x′) with analytic coefficients, and with Q(x,Dx′) second order, principally real and elliptic in Dx′ for x near zero. We show that if Pu=f, u∈C∞, and f is analytic in a neighbourhood of 0, then u is analytic in a neighbourhood of 0.
Jeffrey Galkowski, Maciej Zworski
wiley +2 more sources
(SEMI-)GLOBAL ANALYTIC HYPOELLIPTICITY FOR A CLASS OF "SUMS OF SQUARES" WHICH FAIL TO BE LOCALLY ANALYTIC HYPOELLIPTIC [PDF]
, 2022 The global and semi-global analytic hypoellipticity on the torus is proved for two classes of sums of squares operators, introduced by P. Albano, A. Bove, and M.
Chinni, G
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Enhanced dissipation and Taylor dispersion in higher‐dimensional parallel shear flows
Journal of the London Mathematical Society, Volume 108, Issue 4, Page 1358-1392, October 2023., 2023 Abstract We consider the evolution of a passive scalar advected by a parallel shear flow in an infinite cylinder with bounded cross section, in arbitrary space dimension. The essential parameters of the problem are the molecular diffusivity ν$\nu$, which is assumed to be small, and the wave number k$k$ in the streamwise direction, which can take ...
Michele Coti Zelati, Thierry Gallay
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Time regularity for generalized Mehler semigroups
Mathematische Nachrichten, Volume 295, Issue 11, Page 2223-2245, November 2022., 2022 Abstract We study continuity and Hölder continuity of t↦Ptf$t\mapsto P_tf$, where Pt$P_t$ is a generalized Mehler semigroup in Cb(X)$C_b(X)$, the space of the continuous and bounded functions from a Banach space X to R$\mathbb {R}$, and f∈Cb(X)$f\in C_b(X)$.
Alessandra Lunardi
wiley +1 more source
Manifold Markov chain Monte Carlo methods for Bayesian inference in diffusion models
Journal of the Royal Statistical Society: Series B (Statistical Methodology), Volume 84, Issue 4, Page 1229-1256, September 2022., 2022 Abstract Bayesian inference for nonlinear diffusions, observed at discrete times, is a challenging task that has prompted the development of a number of algorithms, mainly within the computational statistics community. We propose a new direction, and accompanying methodology—borrowing ideas from statistical physics and computational chemistry—for ...
Matthew M. Graham +2 more
wiley +1 more source
Almost Periodic Functions and Their Applications: A Survey of Results and Perspectives
Journal of Mathematics, Volume 2021, Issue 1, 2021., 2021 The main aim of this survey article is to present several known results about vector‐valued almost periodic functions and their applications. We separately consider almost periodic functions depending on one real variable and almost periodic functions depending on two or more real variables.
Wei-Shih Du +3 more
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ANALYTIC HYPOELLIPTICITY for SUMS of SQUARES in the PRESENCE of SYMPLECTIC NON TREVES STRATA [PDF]
, 2020 In Albano, Bove and Mughetti [J. Funct. Anal. 274(10) (2018), 2725-2753]; Bove and Mughetti [Anal. PDE 10(7) (2017), 1613-1635] it was shown that Treves conjecture for the real analytic hypoellipticity of sums of squares operators does not hold.
Bove A., Mughetti M.
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Theory of B(X)‐Module: Algebraic Module Structure of Generally Unbounded Infinitesimal Generators
Advances in Mathematical Physics, Volume 2020, Issue 1, 2020., 2020 The concept of logarithmic representation of infinitesimal generators is introduced, and it is applied to clarify the algebraic structure of bounded and unbounded infinitesimal generators. In particular, by means of the logarithmic representation, the bounded components can be extracted from generally unbounded infinitesimal generators.
Yoritaka Iwata, Ricardo Weder
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Analytic regularity for solutions to sums of squares: an assessment [PDF]
, 2020 We present a brief survey on the state of the theory of the real analytic regularity (real analytic hypoellipticity) for the solutions to sums of squares of vector fields satisfying the Hörmander ...
Bove, Antonio, Mughetti, Marco
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, 2020 In this paper, we present necessary and sufficient conditions to have global analytic hypoellipticity for a class of first-order operators defined on $\mathbb{T}^1 \times \mathbb{S}^3$.
Paleari, Ricardo +5 more
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