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We study universal approximation of continuous functionals on compact subsets of products of Hilbert spaces. We prove that any such functional can be uniformly approximated by models that first take finitely many continuous linear…

Machine Learning · Computer Science 2026-02-04 Andrey Krylov , Maksim Penkin

The main aim of this paper is to show that the nonlinear Choquet integral can be used to construct nonlinear approximation operators, exactly as by the use in probability of the Lebesgue-type integral, linear and positive approximation…

Classical Analysis and ODEs · Mathematics 2016-05-23 Sorin G Gal

Let $-\im\Lie_\T$ (essentially Lie derivative with respect to $\T$, a smooth nowhere zero real vector field) and $P$ be commuting differential operators, respectively of orders 1 and $m\geq 1$, the latter formally normal, both acting on…

Analysis of PDEs · Mathematics 2013-01-25 Gerardo A. Mendoza

We prove an abstract theorem of maximal hypoellipticy showing that in an abstract calculus under some natural assumptions, an operator is maximally hypoelliptic if and only if its principal symbol is left invertible. We then show that our…

Operator Algebras · Mathematics 2026-01-21 Omar Mohsen

This paper is concerned with the hard thresholding operator which sets all but the $k$ largest absolute elements of a vector to zero. We establish a {\em tight} bound to quantitatively characterize the deviation of the thresholded solution…

Machine Learning · Statistics 2020-08-12 Jie Shen , Ping Li

We apply the effective field theory approach to the coupled metric-inflaton system, in order to investigate the impact of higher dimension operators on the spectrum of scalar and tensor perturbations in the short-wavelength regime. In both…

High Energy Physics - Theory · Physics 2009-09-28 Cristian Armendariz-Picon , Michele Fontanini , Riccardo Penco , Mark Trodden

Kochen-Specker theorems assure the breakdown of certain types of non-contextual hidden variable theories through the non-existence of global, holistic frame functions; alas they do not allow us to identify where this breakdown occurs, nor…

Quantum Physics · Physics 2014-03-11 Alastair A. Abbott , Cristian S. Calude , Karl Svozil

We develop the global moduli theory of symplectic varieties in the sense of Beauville. We prove a number of analogs of classical results from the smooth case, including a global Torelli theorem. In particular, this yields a new proof of…

Algebraic Geometry · Mathematics 2022-08-02 Benjamin Bakker , Christian Lehn

We study an analogue of the Mertens conjecture in the setting of global function fields. Building on the work of Cha, we show that most hyperelliptic curves do not satisfy the Mertens conjecture, but that if we modify the Mertens conjecture…

Number Theory · Mathematics 2015-02-25 Peter Humphries

We present a formally verified global optimization framework. Given a semialgebraic or transcendental function $f$ and a compact semialgebraic domain $K$, we use the nonlinear maxplus template approximation algorithm to provide a certified…

Logic in Computer Science · Computer Science 2015-01-06 Victor Magron , Xavier Allamigeon , Stéphane Gaubert , Benjamin Werner

It has been shown that the Cauchy problem for geodesics in the space of K\"ahler metrics with a fixed cohomology class on a compact complex manifold $M$ can be effectively reduced to the problem of finding the flow of a related hamiltonian…

Symplectic Geometry · Mathematics 2019-09-10 José Mourão , João P. Nunes , Tomás Reis

We study the effective action for the massive vector field theory non-minimally coupled to external gravitational field. Such a theory is an interesting model both from the theoretical side and also due to the various phenomenological…

High Energy Physics - Theory · Physics 2017-04-19 Ioseph L. Buchbinder , Tibério de Paula Netto , Ilya L. Shapiro

Let $k$ be a field with a real valuation $\nu$ and $R$ a $k$-algebra. We show that there exist a $k$-algebra $K$ and a real valuation $\mu$ on $K$ extending $\nu$ such that any real ring valuation of $R$ is induced by $\mu$ via some…

Algebraic Geometry · Mathematics 2013-04-30 D. A. Stepanov

Given a complex, elliptic coefficient function we investigate for which values of $p$ the corresponding second-order divergence form operator, complemented with Dirichlet, Neumann or mixed boundary conditions, generates a strongly…

Analysis of PDEs · Mathematics 2019-03-18 A. F. M. ter Elst , R. Haller-Dintelmann , J. Rehberg , P. Tolksdorf

In a mean-field approximation within Kinetic Field Theory, it is possible to derive an accurate analytic expression for the power spectrum of present-day non-linear cosmic density fluctuations. It depends on the theory of gravity and the…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-13 Alexander Oestreicher , Harshda Saxena , Niklas Reinhardt , Elena Kozlikin , Johannes Dombrowski , Matthias Bartelmann

The aim of this paper is to prove new uncertainty principles for an integral operator $\tt$ with a bounded kernel for which there is a Plancherel theorem. The first of these results is an extension of Faris's local uncertainty principle…

Classical Analysis and ODEs · Mathematics 2018-08-27 Saifallah Ghobber , Philippe Jaming

Let h be a real-analytic function in the neighborhood of some compact set K on the plane. We show that for any complex measure on the Euclidean space of a finite total variation without singular components with the Fourier--Stieltjes…

Classical Analysis and ODEs · Mathematics 2021-12-21 Serhii Favorov

Using the gradient expansion approach, we formulate a nonlinear cosmological perturbation theory on super-horizon scales valid to $O(\epsilon^2)$, where $\epsilon$ is the expansion parameter associated with a spatial derivative. For…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Yoshiharu Tanaka , Misao Sasaki

Contrary to common belief, the standard tenet of Brans-Dicke theory reducing to general relativity when omega tends to infinity is false if the trace of the matter energy-momentum tensor vanishes. The issue is clarified in a new approach…

General Relativity and Quantum Cosmology · Physics 2011-08-17 Valerio Faraoni

We consider the space of functions almost in $L_p$ and endow it with the topology of asymptotic $L_p$-convergence. This yields a completely metrizable topological vector space which, on finite measure spaces, coincides with the space of…

Functional Analysis · Mathematics 2025-12-01 Nuno J. Alves
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