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We argue that there should exist a "noncommutative Fourier transform" which should identify functions of noncommutative variables (say, of matrices of indeterminate size) and ordinary functions or measures on the space of paths. Some…

Quantum Algebra · Mathematics 2007-05-23 M. Kapranov

The representations of dimension vector $\alpha$ of the quiver Q can be parametrised by a vector space $R(Q,\alpha)$ on which an algebraic group $\Gl(\alpha)$ acts so that the set of orbits is bijective with the set of isomorphism classes…

Rings and Algebras · Mathematics 2007-05-23 Aidan Schofield , Michel Van den Bergh

The quadratic phase Fourier transform has gained much popularity in recent years because of its applications in image and signal processing. However, the QPFT is inadequate for localizing the quadratic phase spectrum which is required in…

Signal Processing · Electrical Eng. & Systems 2022-03-01 Mohd Younus Bhat , Aamir Hamid Dar , Didar Urynbassarova , Altyn Urynbassarova

We present a decomposition of finitely supported filters ( aka instrument function PSF) as a composition of invertible and non-invertible filters. The invertible component can be inverted directly and the non-invertible component is shown…

Numerical Analysis · Mathematics 2022-05-17 Yury Tyurin , Anastasia Tyurina

Consider $d$ disjoint closed subintervals of the unit interval and consider an orientation preserving expanding map which maps each of these subintervals to the whole unit interval. The set of points where all iterates of this expanding map…

Dynamical Systems · Mathematics 2008-02-03 Feliks Przytycki , Folkert Tangerman

In this paper we focus on the solution of shifted quasiseparable systems and of more general parameter dependent matrix equations with quasiseparable representations. We propose an efficient algorithm exploiting the invariance of the…

Numerical Analysis · Mathematics 2017-08-07 Paola Boito , Yuli Eidelman , Luca Gemignani

This comprehensive review paper delves into the intricacies of advanced Fourier type integral transforms and their mathematical properties, with a particular focus on fractional Fourier transform (FrFT), linear canonical transform (LCT),…

Classical Analysis and ODEs · Mathematics 2024-02-13 Bivek Gupta , Amit K. Verma

We define the holomorphic Fourier transform of holomorphic functions on complex reductive groups, prove some properties like the Fourier inversion formula, and give some applications. The definition of the holomorphic Fourier transform…

Group Theory · Mathematics 2007-09-05 Jinpeng An , Zhengdong Wang , Min Qian

We define a Markov process on the set of countable graphs with spins. Transitions are local substitutions in the graph. It is proved that the scaling macrodimension is an invariant of such dynamics.

Mathematical Physics · Physics 2012-01-23 V. A. Malyshev

We present a general setting where wavelet filters and multiresolution decompositions can be defined, beyond the classical $\mathbf L^2(\mathbb R,dx)$ setting. This is done in a framework of {\em iterated function system} (IFS) measures;…

Functional Analysis · Mathematics 2022-08-31 Daniel Alpay , Palle Jorgensen , Izchak Lewkowicz

The quadratic phase Fourier transform QPFT is a neoteric addition to the class of Fourier transforms and embodies a variety of signal processing tools including the Fourier, fractional Fourier, linear canonical, and special affine Fourier…

Functional Analysis · Mathematics 2022-07-21 Aamir H. Dar , M. Younus Bhat

For a class of piecewise deterministic Markov processes, the supports of the invariant measures are characterized. This is based on the analysis of controllability properties of an associated deterministic control system. Its invariant…

Dynamical Systems · Mathematics 2018-04-05 Michel Benaïm , Fritz Colonius , Lettau Ralph

The quantum Fourier transform for discrete variable (dvQFT) is an efficient algorithm for several applications. It is usually considered for the processing of quantum bits (qubits) and its efficient implementation is obtained with two…

Quantum Physics · Physics 2025-12-16 Gianfranco Cariolaro , Edi Ruffa , Amir Mohammad Yaghoobianzadeh , Jawad A. Salehi

A novel addition to the family of integral transforms, the quadratic phase Fourier transform (QPFT) embodies a variety of signal processing tools, including the Fourier transform (FT), fractional Fourier transform (FRFT), linear canonical…

Functional Analysis · Mathematics 2024-02-20 Aamir Hamid Dar

We consider finite approximations of a fractal generated by an iterated function system of affine transformations on $\mathbb{R}^d$ as a discrete set of data points. Considering a signal supported on this finite approximation, we propose a…

Functional Analysis · Mathematics 2016-07-14 Calvin Hotchkiss , Eric S. Weber

We study the problem of designing models for machine learning tasks defined on \emph{sets}. In contrast to traditional approach of operating on fixed dimensional vectors, we consider objective functions defined on sets that are invariant to…

Machine Learning · Computer Science 2018-04-17 Manzil Zaheer , Satwik Kottur , Siamak Ravanbakhsh , Barnabas Poczos , Ruslan Salakhutdinov , Alexander Smola

By the Fourier transformations, any group-invariant functions over finite Abelian groups are transformed into group-invariant functions over the character groups. In this paper, we calculate matrix elements of this transformations under…

Representation Theory · Mathematics 2020-09-01 Koei Kawamura

Fractals equipped with intrinsic arithmetic lead to a natural definition of differentiation, integration and complex numbers. Applying the formalism to the problem of a Fourier transform on fractals we show that the resulting transform has…

Mathematical Physics · Physics 2016-07-26 Diederik Aerts , Marek Czachor , Maciej Kuna

We consider the notion of the matrix (tensor) distribution of a measurable function of several variables. On the one hand, it is an invariant of this function with respect to a certain group of transformations of variables; on the other…

Dynamical Systems · Mathematics 2023-11-03 A. Vershik

We offer a new proof that a certain q-analogue of multinomial coeffi- cients furnishes a q-counting of the set of permutations of an associated multiset of positive integers, according to the number of inversions in such arrangements. Our…

Combinatorics · Mathematics 2018-08-28 Shashikant Mulay , Carl Wagner