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Related papers: A New Hypoelliptic Operator on Almost CR Manifolds

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For a large class of semiclassical pseudodifferential operators, including Schr\"odinger operators, $ P (h) = -h^2 \Delta_g + V (x) $, on compact Riemannian manifolds, we give logarithmic lower bounds on the mass of eigenfunctions outside…

Spectral Theory · Mathematics 2009-08-18 Hans Christianson

We prove the complex powers of a class of infinite order hypoelliptic pseudodifferential operators can always be represented as hypoelliptic pseudodifferential operators modulo ultrasmoothing operators. We apply this result to the study of…

Functional Analysis · Mathematics 2017-12-18 Stevan Pilipović , Bojan Prangoski

We study the most general class of eigenfunction expansions for abstract normal operators with pure point spectrum in a complex Hilbert space. We find sufficient conditions for such expansions to be unconditionally convergent in spaces with…

Functional Analysis · Mathematics 2026-01-14 Vladimir Mikhailets , Aleksandr Murach

In this paper we prove sufficient conditions for the Fredholm property of a non-smooth pseudodifferential operator $P$ which symbol is in a H\"older space with respect to the spatial variable. As a main ingredient for the proof we use a…

Functional Analysis · Mathematics 2018-06-05 Helmut Abels , Christine Pfeuffer

We study the relationship between recent conjectures on slopes of overconvergent p-adic modular forms "near the boundary" of p-adic weight space. We also prove in tame level 1 that the coefficients of the Fredholm series of the U_p operator…

Number Theory · Mathematics 2017-02-28 John Bergdall , Robert Pollack

In this paper we establish a unilateral bifurcation result for a class of quasilinear elliptic system strongly coupled, extending a bifurcation theorem due to J. L\'opez-G\'omez. To this aim, we use several results, such that Fredholm…

Analysis of PDEs · Mathematics 2018-02-27 Willian Cintra , Cristian Morales-Rodrigo , António Suárez

We study a special type of almost complex structures, called pure and full and introduced by T.J. Li and W. Zhang, in relation to symplectic structures and Hard Lefschetz condition. We provide sufficient conditions to the existence of the…

Differential Geometry · Mathematics 2009-06-04 Anna Fino , Adriano Tomassini

We investigate elliptic operators with a symmetry that forces their index to vanish. We study the secondary index, defined modulo 2. We examine Callias-type operators with this symmetry on non-compact manifolds and establish mod 2 versions…

Differential Geometry · Mathematics 2024-12-05 Maxim Braverman , Ahmad Reza Haj Saeedi Sadegh

In the context of an infinite locally finite weighted graph, we give a necessary and sufficientcondition for semi-Fredholmness of the Gauss-Bonnet operator. This result is a discrete version of thetheorem of Gilles Carron in the continuous…

Functional Analysis · Mathematics 2016-12-13 Hèla Ayadi

This research comprehensively describes the basic theory of transversally Heisenberg elliptic operators, and investigates the index theory of Heisenberg elliptic and transversally Heisenberg elliptic operators from the perspective of…

K-Theory and Homology · Mathematics 2025-01-22 Minjie Tian

In [1], a new quasi-Hermitian variety $\mathcal{H}_\varepsilon^r$ in $\mathrm{PG}(r, q^2)$, with $q = 2^e$ and $e \geq 3$ an odd integer, was constructed. The variety depends on a primitive element $\varepsilon$ of the underlying field…

Combinatorics · Mathematics 2025-08-07 Angela Aguglia , Alessandro Montinaro

We introduce the trace operator for quasi-plurisubharmonic functions on compact K\"ahler manifolds, allowing to study the singularities of such functions along submanifolds where their generic Lelong numbers vanish. Using this construction…

Differential Geometry · Mathematics 2026-03-16 Tamás Darvas , Mingchen Xia

We propose a more direct approach to constructing differential operators that preserve polynomial subspaces than the one based on considering elements of the enveloping algebra of sl(2). This approach is used here to construct new exactly…

Exactly Solvable and Integrable Systems · Physics 2009-11-10 D. Gomez-Ullate , N. Kamran , R. Milson

In this note, we look at some hypoelliptic operators arising from nilpotent rank 2 Lie algebras. In particular, we concentrate on the diffusion generated by three Brownian motions and their three L\'evy areas, which is the simplest…

Probability · Mathematics 2010-07-28 Bin Qian

In this note, by analyzing the behavior at infinity of the matrix symbol of an invariant operator $P$ with respect to a fixed elliptic operator, we obtain a necessary and sufficient condition to guarantee that $P$ is globally hypoelliptic.…

Analysis of PDEs · Mathematics 2020-01-17 Alexandre Kirilov , Wagner Augusto Almeida de Moraes

We show that the existence of a Fredholm element of the zero calculus of pseudodifferential operators on a compact manifold with boundary with a given elliptic symbol is determined, up to stability, by the vanishing of the Atiyah-Bott…

Differential Geometry · Mathematics 2010-12-30 Pierre Albin , Richard Melrose

In this article we introduce the notion of Floer function which has the property that the Hessian is a Fredholm operator of index zero in a scale of Hilbert spaces. Since the Hessian has a complicated transformation under chart transition,…

Symplectic Geometry · Mathematics 2025-02-04 Urs Frauenfelder , Joa Weber

We present an improved Fredholm theory of non-elliptic operators for when the corresponding classical dynamical system exhibits normally hyperbolic trapping with smooth backward and forward trapped sets. It takes place on coisotropic…

Analysis of PDEs · Mathematics 2025-10-21 Selim Amar

A classical problem in operator theory has been to determine the spectrum of Toeplitz-like operators on Hilbert spaces of vector-valued holomorphic functions on the open unit ball in C^m. In this note we obtain necessary conditions for…

Operator Algebras · Mathematics 2009-03-02 Ronald G. Douglas , Jaydeb Sarkar

We establish an $\mathrm{L}^p$-index theorem for Dolbeault--Dirac operators on compact K\"ahler manifolds with coefficients in a Hermitian holomorphic vector bundle $E$. For every $p \in (1,\infty)$, we prove that the closed…

Functional Analysis · Mathematics 2026-05-21 Cédric Arhancet