English
Related papers

Related papers: Wishart Processes

200 papers

The sum of independent Wishart matrices, taken from distributions with unequal covariance matrices, plays a crucial role in multivariate statistics, and has applications in the fields of quantitative finance and telecommunication. However,…

Mathematical Physics · Physics 2014-09-23 Santosh Kumar

In this work, we consider the weighted difference of two independent complex Wishart matrices and derive the joint probability density function of the corresponding eigenvalues in a finite-dimension scenario using two distinct approaches.…

Mathematical Physics · Physics 2020-11-17 Santosh Kumar , S. Sai Charan

The signaling capacity of a neural population depends on the scale and orientation of its covariance across trials. Estimating this "noise" covariance is challenging and is thought to require a large number of stereotyped trials. New…

Applications · Statistics 2023-11-01 Amin Nejatbakhsh , Isabel Garon , Alex H Williams

Recent work introduced deep kernel processes as an entirely kernel-based alternative to NNs (Aitchison et al. 2020). Deep kernel processes flexibly learn good top-layer representations by alternately sampling the kernel from a distribution…

Machine Learning · Statistics 2021-12-06 Sebastian W. Ober , Laurence Aitchison

To explore the limits of a stochastic gradient method, it may be useful to consider an example consisting of an infinite number of quadratic functions. In this context, it is appropriate to determine the expected value and the covariance…

Optimization and Control · Mathematics 2022-12-14 Melinda Hagedorn

We establish an explicit expression for the conditional Laplace transform of the integrated Volterra Wishart process in terms of a certain resolvent of the covariance function. The core ingredient is the derivation of the conditional…

Probability · Mathematics 2024-07-09 Eduardo Abi Jaber

The paper "An efficient sampling scheme for the eigenvalues of dual Wishart matrices", by I.~Santamar\'ia and V.~Elvira, [\emph{IEEE Signal Processing Letters}, vol.~28, pp.~2177--2181, 2021] \cite{SE21}, poses the question of efficient…

Statistics Theory · Mathematics 2024-01-24 Peter J. Forrester

The literature presents the characteristic function of the Wishart distribution on m times m matrices as an inverse power of the determinant of the Fourier variable, the exponent being the positive, real shape parameter. I demonstrate that…

Probability · Mathematics 2019-01-29 Eberhard Mayerhofer

We investigate the Student-t process as an alternative to the Gaussian process as a nonparametric prior over functions. We derive closed form expressions for the marginal likelihood and predictive distribution of a Student-t process, by…

Machine Learning · Statistics 2014-02-20 Amar Shah , Andrew Gordon Wilson , Zoubin Ghahramani

We study the behavior of a real $p$-dimensional Wishart random matrix with $n$ degrees of freedom when $n,p\rightarrow\infty$ but $p/n\rightarrow 0$. We establish the existence of phase transitions when $p$ grows at the order…

Probability · Mathematics 2017-05-11 Didier Chételat , Martin T. Wells

In complex systems, crucial parameters are often subject to unpredictable changes in time. Climate, biological evolution and networks provide numerous examples for such non-stationarities. In many cases, improved statistical models are…

Statistical Finance · Quantitative Finance 2015-12-09 Frederik Meudt , Martin Theissen , Rudi Schäfer , Thomas Guhr

Random quantum states are useful in various areas of quantum information science. Distributions of random quantum states using Gaussian distributions have been used in various scenarios in quantum information science. One of this is the…

Quantum Physics · Physics 2024-01-24 Shrobona Bagchi

The noncentral Wishart distribution has become more mainstream in statistics as the prevalence of applications involving sample covariances with underlying multivariate Gaussian populations as dramatically increased since the advent of…

Statistics Theory · Mathematics 2022-05-25 Frédéric Ouimet

In this work we study the spectral density of products of Wishart diluted random matrices of the form $X(1)\cdots X(M)(X(1)\cdots X(M))^T$ using the Edwards-Jones trick to map this problem into a system of interacting particles with random…

Disordered Systems and Neural Networks · Physics 2014-07-25 Thomas Dupic , Isaac Pérez Castillo

We calculate the `one-point function', meaning the marginal probability density function for any single eigenvalue, of real and complex Wishart correlation matrices. No explicit expression had been obtained for the real case so far. We…

Statistics Theory · Mathematics 2015-03-17 Christian Recher , Mario Kieburg , Thomas Guhr , Martin R. Zirnbauer

We show that the derivative of the logarithm of the average characteristic polynomial of a diffusing Wishart matrix obeys an exact partial differential equation valid for an arbitrary value of N, the size of the matrix. In the large N…

Mathematical Physics · Physics 2015-12-23 Jean-Paul Blaizot , Maciej A. Nowak , Piotr Warchoł

Wavelets provide the flexibility to analyse stochastic processes at different scales. Here, we apply them to multivariate point processes as a means of detecting and analysing unknown non-stationarity, both within and across data streams.…

Methodology · Statistics 2020-11-04 Edward A. K. Cohen , Alexander J. Gibberd

This paper is devoted to the study of the eigenvalues of the Wishart process which are the analogof the Dyson Brownian Motion for covariance matrices. Such processes were in particular studied byBru. The mean field convergence of the…

Probability · Mathematics 2021-05-11 Ezechiel Kahn

A novel approach called Moate Simulation is presented to provide an accurate numerical evolution of probability distribution functions represented on grids arising from stochastic differential processes where initial conditions are…

Computational Finance · Quantitative Finance 2022-12-19 Michael E. Mura

Using a character expansion method, we calculate exactly the eigenvalue density of random matrices of the form M^\dagger M where M is a complex matrix drawn from a normalized distribution P(M) ~ exp(-\Tr(A M B M^\dagger) with A and B…

Mathematical Physics · Physics 2009-11-10 Steven H. Simon , Aris L. Moustakas