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Related papers: Estimates of perturbation series for kernels

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This study explores the utility of a kernel in complex Langevin simulations of quantum real-time dynamics on the Schwinger-Keldysh contour. We give several examples where we use a systematic scheme to find kernels that restore correct…

High Energy Physics - Lattice · Physics 2022-11-22 Daniel Alvestad , Rasmus Larsen , Alexander Rothkopf

We discuss one natural class of kernels on pseudo-Riemannian symmetric spaces.

Representation Theory · Mathematics 2012-11-27 Yuri A. Neretin

We consider the linear and non linear cubic Schr\"odinger equations with periodic boundary conditions, and their approximations by splitting methods. We prove that for a dense set of arbitrary small time steps, there exists numerical…

Numerical Analysis · Mathematics 2013-11-20 Erwan Faou , Tiphaine Jézéquel

Perturbation series for the electron propagator in the Schwinger Model is summed up in a direct way by adding contributions coming from individual Feynman diagrams. The calculation shows the complete agreement between nonperturbative and…

High Energy Physics - Theory · Physics 2011-09-13 Tomasz Radozycki

In this paper, we show that the presence of nonlinear coupling between time series may be detected employing kernel feature space representations alone dispensing with the need to go back to solve the pre-image problem to gauge model…

Signal Processing · Electrical Eng. & Systems 2019-07-24 Lucas Massaroppe , Luiz A. Baccalá

We study a family of integrable systems of nonlinearly coupled harmonic oscillators on the classical and quantum levels. We show that the integrability of these systems follows from their symmetry characterized by algebras called here…

Mathematical Physics · Physics 2016-06-22 A. Odzijewicz , E. Wawreniuk

This study explores the utility of a kernel in complex Langevin simulations of quantum real-time dynamics on the Schwinger-Keldysh contour. We give several examples where we use a systematic scheme to find kernels that restore correct…

High Energy Physics - Lattice · Physics 2022-12-16 Daniel Alvestad , Rasmus Larsen , Alexander Rothkopf

As helioseismology matures and turns into a precision science, modeling finite-frequency, geometric and systematical effects is becoming increasingly important. Here we introduce a general formulation for treating perturbations of arbitrary…

Solar and Stellar Astrophysics · Physics 2020-09-16 Jishnu Bhattacharya , Shravan M. Hanasoge , Katepalli R. Sreenivasan

By suitably extending a Feynman-Kac formula of Simon [Canadian Math. Soc. Conf. Proc, 28 (2000), 317-321], we study one-parameter semigroups generated by (the negative of) rather general Schroedinger operators, which may be unbounded from…

Mathematical Physics · Physics 2007-05-23 Kurt Broderix , Hajo Leschke , Peter Müller

The problem of estimating the kernel mean in a reproducing kernel Hilbert space (RKHS) is central to kernel methods in that it is used by classical approaches (e.g., when centering a kernel PCA matrix), and it also forms the core inference…

Machine Learning · Statistics 2014-11-05 Krikamol Muandet , Bharath Sriperumbudur , Bernhard Schölkopf

We introduce the notion of multiplication kernels of birational and $D$-module type and give various examples. We also introduce the notion of a semi-classical multiplication kernel associated with an integrable system and discuss its…

Algebraic Geometry · Mathematics 2022-01-05 Maxim Kontsevich , Alexander Odesskii

We give a characterization of a variation of constants type estimate relating two positive semigroups on (possibly different) $L_p$-spaces to one another in terms of corresponding estimates for the respective generators and of estimates for…

Functional Analysis · Mathematics 2016-06-28 Christian Seifert , Marcus Waurick

We distinguish two extreme classes of perturbation problems depending on the signs of second-order energy corrections and argue why it is generally much more probable to obtain a negative value of the same for any state in the standard…

Quantum Physics · Physics 2019-11-14 Kamal Bhattacharyya

We consider inverse dynamical, spectral, quantum and acoustical scattering problems for the Schr\"odinger operator on the half line. The goal of the paper is to establish the connections between different types of inverse data for these…

Analysis of PDEs · Mathematics 2025-05-15 A. S. Mikhaylov , V. S. Mikhaylov

We introduce the theory of non-linear cosmological perturbations using the correspondence limit of the Schr\"odinger equation. The resulting formalism is equivalent to using the collisionless Boltzman (or Vlasov) equations which remain…

Astrophysics · Physics 2009-11-07 Istvan Szapudi , Nick Kaiser

We extend some recent results of Lubinsky, Levin, Simon, and Totik from measures with compact support to spectral measures of Schr\"odinger operators on the half-line. In particular, we define a reproducing kernel $S_L$ for Schr\"odinger…

Mathematical Physics · Physics 2009-08-12 Anna Maltsev

The universality properties of kernels characterize the class of functions that can be approximated in the associated reproducing kernel Hilbert space and are of fundamental importance in the theoretical underpinning of kernel methods in…

Machine Learning · Computer Science 2025-06-25 Franziskus Steinert , Salem Said , Cyrus Mostajeran

The present work develops certain analytical tools required to construct and compute invariant kernels on the space of complex covariance matrices. The main result is the $\mathrm{L}^1$--Godement theorem, which states that any invariant…

Functional Analysis · Mathematics 2025-04-17 Salem Said , Franziskus Steinert , Cyrus Mostajeran

$C^*$-algebra-valued kernels could pave the way for the next generation of kernel machines. To further our fundamental understanding of learning with $C^*$-algebraic kernels, we propose a new class of positive definite kernels based on the…

Machine Learning · Statistics 2025-03-11 Yuka Hashimoto , Ayoub Hafid , Masahiro Ikeda , Hachem Kadri

In spatial statistics, kriging models are often designed using a stationary covariance structure; this translation-invariance produces models which have numerous favorable properties. This assumption can be limiting, though, in…

Computation · Statistics 2018-12-04 Michael McCourt , Gregory Fasshauer , David Kozak