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Related papers: Some constants related to numerical ranges

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We investigate the fluctuations of linear spectral statistics of a Wigner matrix $W\_N$ deformed by a deterministic diagonal perturbation $D\_N$, around a deterministic equivalent which can be expressed in terms of the free convolution…

Probability · Mathematics 2020-03-17 Sandrine Dallaporta , Maxime Fevrier

We present an overarching framework for stable spectral methods on a triangle, defined by a multivariate W-system and based on orthogonal polynomials on the triangle. Motivated by the Koornwinder orthogonal polynomials on the triangle, we…

Numerical Analysis · Mathematics 2024-08-05 Jing Gao , Arieh Iserles

We investigate three-point statistics in weak lensing convergence, through the integrated bispectrum. This statistic involves measuring power spectra in patches, and is thus easy to measure, and avoids the complexity of estimating the very…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-13 Gabriel Jung , Toshiya Namikawa , Michele Liguori , Dipak Munshi , Alan Heavens

We derive concentration inequalities for the spectral measure of large random matrices, allowing for certain forms of dependence. Our main focus is on empirical covariance (Wishart) matrices, but general symmetric random matrices are also…

Statistics Theory · Mathematics 2018-09-24 Adityanand Guntuboyina , Hannes Leeb

We review some of the recent developments in the construction of $W$-string theories. These are generalisations of ordinary strings in which the two-dimensional ``worldsheet'' theory, instead of being a gauging of the Virasoro algebra, is a…

High Energy Physics - Theory · Physics 2007-05-23 C. N. Pope

Studying the geometry of sets appearing in various problems of quantum information helps in understanding different parts of the theory. It is thus worthwhile to approach quantum mechanics from the angle of geometry -- this has already…

Quantum Physics · Physics 2023-03-15 Konrad Szymański

Various contributions to the cosmological constant are discussed and confronted with its recent measurement. We briefly review different scenarious -- and their difficulties -- for a solution of the cosmological constant problem.

High Energy Physics - Phenomenology · Physics 2017-08-23 U. Ellwanger

We present some classical and weighted Poincar\'e inequalities for some one-dimensional probability measures. This work is the one-dimensional counterpart of a recent study achieved by the authors for a class of spherically symmetric…

Probability · Mathematics 2014-11-24 Michel Bonnefont , Aldéric Joulin , Yutao Ma

We consider large-dimensional Hermitian or symmetric random matrices of the form $W=M+\vartheta V$ where $M$ is a Wigner matrix and $V$ is a real diagonal matrix whose entries are independent of $M$. For a large class of diagonal matrices…

Probability · Mathematics 2019-04-22 Hong Chang Ji , Ji Oon Lee

We study some spectral properties of a matrix that is constructed as a combination of a Laplacian and an adjacency matrix of simple graphs. The matrix considered depends on a positive parameter, as such we consider the implications in…

Dynamical Systems · Mathematics 2024-08-02 Riccardo Bonetto , Hildeberto Jardón Kojakhmetov

We obtain a sufficient condition for the convexity of quaternionic numerical range for complex matrices in terms of its complex numerical range. It is also shown that the Bild coincides with complex numerical range for real matrices. From…

Functional Analysis · Mathematics 2019-04-08 Luís Carvalho , Cristina Diogo , Sérgio Mendes

The spectra of random feature matrices provide essential information on the conditioning of the linear system used in random feature regression problems and are thus connected to the consistency and generalization of random feature models.…

Machine Learning · Statistics 2022-12-13 Zhijun Chen , Hayden Schaeffer , Rachel Ward

In this paper we investigate the spectral norm for circulant matrices, whose entries are modified Fibonacci numbers and Lucas numbers. We obtain the identity estimations for the spectral norms. Some numerical test results are listed to…

Numerical Analysis · Mathematics 2026-05-29 Jianwei Zhou , Zhaolin Jiang

The process of a stationary range formation in the wind-wave spectrum is investigated numerically. The evolution equation for the two-dimensional wind-wave spectrum is numerically solved by using an exact calculation of the Hasselmann…

Atmospheric and Oceanic Physics · Physics 2018-01-30 Vladislav G. Polnikov , Fangli Qiao , Jing Lu

We experiment with some topics in elementary number theory. For matrices defined by Gaussian primes we observe a circular spectral law for the eigenvalues. We look at matrices defined by Gaussian primes and look at the growth of the…

Number Theory · Mathematics 2016-06-21 Oliver Knill

The boundary of a numerical range of a finite matrix is always a nice curve (algebraic, closed and simple), but the equation it satisfies is often very complicated. We will show that, furthermore, there is no hope of describing these curves…

History and Overview · Mathematics 2025-07-10 Petr Blaschke

The search for variation of the fundamental constants such as the fine structure constant $\alpha$ ($\alpha=e^2/\hbar c$) and the ratios of fundamental masses (e.g., electron to proton mass ratio $\mu=m_e/m_p$) is reviewed. Strong emphasis…

Atomic Physics · Physics 2015-05-13 V. V. Flambaum , V. A. Dzuba

The notion of the higher rank numerical range $\Lambda_{k}(L(\lambda))$ for matrix polynomials $L(\lambda)=A_{m}\lambda^{m}+...+A_{1}\lambda+A_{0}$ is introduced here and some fundamental geometrical properties are investigated. Further,…

Rings and Algebras · Mathematics 2011-04-08 Aikaterini Aretaki , John Maroulas

In this note, we investigate a mixture of combinatorial spectra and stratified simplicial sets, which would be thought of as a model of the spectrum objects of $(\infty, \infty)$-categories.

Algebraic Topology · Mathematics 2023-12-19 Ryo Horiuchi

A short proof of the elliptical range theorem concerning the numerical range of $2\times2$ complex matrices is given.

Spectral Theory · Mathematics 2022-11-24 Gyula Lakos