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This paper presents and analyzes the first matrix optimization model which allows general coordinate and spectral constraints. The breadth of problems our model covers is exemplified by a lengthy list of examples from the literature,…

Optimization and Control · Mathematics 2024-10-15 Casey Garner , Gilad Lerman , Shuzhong Zhang

A finite element methodology for large classes of variational boundary value problems is defined which involves discretizing two linear operators: (1) the differential operator defining the spatial boundary value problem; and (2) a Riesz…

Numerical Analysis · Mathematics 2017-12-08 Brendan Keith , Socratis Petrides , Federico Fuentes , Leszek Demkowicz

We discuss the exclusive radiative decays B -> K* gamma and B -> rho gamma in QCD factorization within the Standard Model. The analysis is based on the heavy-quark limit of QCD. Our results for these decays are complete to next-to-leading…

High Energy Physics - Phenomenology · Physics 2010-11-23 Stefan W. Bosch

We review our perturbative techniques for improved heavy quark actions. A new procedure for computing improvement coefficients is suggested, where the continuum limit of a lattice-regularized theory provides the matching conditions.We also…

High Energy Physics - Lattice · Physics 2009-11-10 Matthew Nobes , Howard Trottier

The eigenproblem of low-rank updated matrices are of crucial importance in many applications. Recently, an upper bound on the number of distinct eigenvalues of a perturbed matrix was established. The result can be applied to estimate the…

Numerical Analysis · Mathematics 2017-08-14 Yunjie Wang , Gang Wu

Polynomial factorization in conventional sense is an ill-posed problem due to its discontinuity with respect to coefficient perturbations, making it a challenge for numerical computation using empirical data. As a regularization, this paper…

Numerical Analysis · Mathematics 2021-03-09 Wenyuan Wu , Zhonggang Zeng

We suggest a new solution to the strong CP problem. The solution is based on the proper use of the boundary conditions for the QCD generating functional integral. We expand the perturbative boundary conditions to both perturbative and…

High Energy Physics - Phenomenology · Physics 2023-12-19 S. A. Larin

We perturb a real matrix $A$ of full column rank, and derive lower bounds for the smallest singular values of the perturbed matrix, in terms of normwise absolute perturbations. Our bounds, which extend existing lower-order expressions,…

Numerical Analysis · Mathematics 2024-02-22 Christos Boutsikas , Petros Drineas , Ilse C. F. Ipsen

Fracton topological phases have a large number of materialized symmetries that enforce a rigid structure on their excitations. Remarkably, we find that the symmetries of a quantum error-correcting code based on a fracton phase enable us to…

Quantum Physics · Physics 2020-04-02 Benjamin J. Brown , Dominic J. Williamson

We use the methods developed with M. Lyubich for proving complex bounds for real quadratics to extend E. De Faria's complex a priori bounds to all critical circle maps with an irrational rotation number. The contracting property for…

Dynamical Systems · Mathematics 2016-09-06 Michael Yampolsky

By defining two important terms called basic perturbation vectors and obtaining their linear bounds, we obtain the linear componentwise perturbation bounds for unitary factors and upper triangular factors of the generalized Schur…

Numerical Analysis · Mathematics 2022-04-21 Guihua Zhang , Hanyu Li , Yimin Wei

We study implicit regularization when optimizing an underdetermined quadratic objective over a matrix $X$ with gradient descent on a factorization of $X$. We conjecture and provide empirical and theoretical evidence that with small enough…

Machine Learning · Statistics 2017-05-26 Suriya Gunasekar , Blake Woodworth , Srinadh Bhojanapalli , Behnam Neyshabur , Nathan Srebro

Recent theoretical investigations of two-body hadronic B decays have provided justification for the use of the factorization ansatz to evaluate the B decay matrix elements. Motivated by this, we present simplified formulae for a wide range…

High Energy Physics - Phenomenology · Physics 2008-11-26 W. N. Cottingham , I. B. Whittingham , N. de Groot , F. Wilson

We introduce and analyze a robust nonconforming finite element method for a three dimensional singularly perturbed quad-curl model problem. For the solution of the model problem, we derive proper a priori bounds, based on which, we prove…

Numerical Analysis · Mathematics 2022-06-27 Baiju Zhang , Zhimin Zhang

Based on the column pivoted QR decomposition, we propose some randomized algorithms including pass-efficient ones for the generalized CUR decompositions of matrix pair and matrix triplet. Detailed error analyses of these algorithms are…

Numerical Analysis · Mathematics 2023-03-14 Guihua Zhang , Hanyu Li , Yimin Wei

The dynamics of the nuclear-spin quantum computer with large number (L=1000) of qubits is considered using a perturbation approach, based on approximate diagonalization of exponentially large sparse matrices. Small parameters are introduced…

Quantum Physics · Physics 2007-05-23 G. P. Berman , D. I. Kamenev , V. I. Tsifrinovich

This paper presents a unified matrix factorization framework for classical and robust clustering. We begin by revisiting the well-known equivalence between crisp k-means clustering and matrix factorization, following and rigorously…

Machine Learning · Computer Science 2025-10-27 Angshul Majumdar

Since b quark mass is not asymptotically large, chirally enhanced corrections which arise from twist-3 wave functions may be important in B decays. We thus evaluate the hadronic matrix elements with the emitted meson described by leading…

High Energy Physics - Phenomenology · Physics 2007-05-23 Dongsheng Du , Deshan Yang , Guohuai Zhu

In the heavy-quark limit, the hadronic matrix elements entering nonleptonic $B$-meson decays into two light mesons can be calculated from first principles including ``nonfactorizable'' strong-interaction corrections. The $B\to\pi K,\pi\pi$…

High Energy Physics - Phenomenology · Physics 2010-05-28 M. Beneke , G. Buchalla , M. Neubert , C. T. Sachrajda

The perturbation theory for critical points of causal variational principles is developed. We first analyze the class of perturbations obtained by multiplying the universal measure by a weight function and taking the push-forward under a…

Mathematical Physics · Physics 2020-08-26 Felix Finster