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Concept

Transformation inverse de Laplace

Publications associées (17)

The Källén-Lehmann representation in de Sitter spacetime

João Miguel Augusto Penedones Fernandes, Kamran Salehi Vaziri, Manuel Loparco

We study two-point functions of symmetric traceless local operators in the bulk of de Sitter spacetime. We derive the Kallen-Lehmann spectral decomposition for any spin and show that unitarity implies its spectral densities are nonnegative. In addition, we ...

Springer Nature2023

Hyperbolic Fourier series

Maryna Viazovska

In this article we explain the essence of the interrelation described in [PNAS 118, 15 (2021)] on how to write explicit interpolation formula for solutions of the Klein-Gordon equation by using the recent Fourier pair interpolation formula of Viazovska and ...

arXiv2021

Nonperturbative Mellin Amplitudes

João Pedro Alves Da Silva

Conformal field theory lies at the heart of two central topics in theoretical high energy physics: the study of quantum gravity and the mapping of quantum field theories through the renormalization group. In this thesis we explore a technique to study conf ...

EPFL2021

The sliding Frank-Wolfe algorithm and its application to super-resolution microscopy

Emmanuel Emilien Louis Soubies, Quentin Alain Denoyelle

This paper showcases the theoretical and numerical performance of the Sliding Frank-Wolfe, which is a novel optimization algorithm to solve the BLASSO sparse spikes super-resolution problem. The BLASSO is a continuous (i.e. off-the-grid or grid-less) count ...

2020

Dynamics of optical forces and torques in plasmonic systems: a surface integral equation

Olivier Martin, Karim Achouri, Andrei Kiselev

A novel approach is introduced to determine the time evolution of optical forces and torques on arbitrary shape nanostructures by combining Maxwell's stress tensor with the surface integral equation method (SIE). Conventional time averaging of Maxwell’s st ...

SPIEDigitalLibrary2020

Fractional extreme distributions

Lotfi Boudabsa

We consider three classes of linear differential equations on distribution functions, with a fractional order alpha is an element of [0; 1]. The integer case alpha = 1 corresponds to the three classical extreme families. In general, we show that there is a ...

2020

Fourier interpolation on the real line

Maryna Viazovska

In this paper we construct an explicit interpolation formula for Schwartz functions on the real line. The formula expresses the value of a function at any given point in terms of the values of the function and its Fourier transform on the set {0,+/- 1,+/- ...

2019

On Short Sums Of Trace Functions

Philippe Michel, Chandra Sekhar Raju

We consider sums of oscillating functions on intervals in cyclic groups of size close to the square root of the size of the group. We first prove non-trivial estimates for intervals of length slightly larger than this square root (bridging the "Polya-Vinog ...

Annales Inst Fourier2017

Analytical Time-Domain Solution of Plane Wave Propagation Across a Viscoelastic Rock Joint

Lyesse Laloui, Jian Zhao, Yang Zou

The effects of viscoelastic filled rock joints on wave propagation are of great significance in rock engineering. The solutions in time domain for plane longitudinal ( P-) and transverse ( S-) waves propagation across a viscoelastic rock joint are derived ...

Springer Verlag2017

An Improved Approach for the Calculation of the Transient Ground Resistance Matrix of Multiconductor Lines

Farhad Rachidi-Haeri

The general integral expressions for the elements of the ground impedance matrix do not have an analytical inverse transform in the time domain. Therefore, the ground transient resistance of a multiconductor line is commonly evaluated in the time domain by ...

Ieee-Inst Electrical Electronics Engineers Inc2016

Superresolution Reconstruction for Magnetic Resonance Spectroscopic Imaging Exploiting Low-Rank Spatio-Spectral Structure

Jeffrey Adam Kasten

Magnetic resonance spectroscopic imaging (MRSI) is a rapidly developing medical imaging modality, capable of conferring both spatial and spectral information content, and has become a powerful clinical tool. The ability to non-invasively observe spatial ma ...

EPFL2015

Ellipse-Preserving Hermite Interpolation and Subdivision

Michaël Unser

We introduce a family of piecewise-exponential functions that have the Hermite interpolation property. Our design is motivated by the search for an effective scheme for the joint interpolation of points and associated tangents on a curve with the ability t ...

Elsevier2015

Scale-invariant representation of light field images for object recognition and tracking

Martin Vetterli, Alireza Ghasemi

Achieving perfect scale-invariance is usually not possible using classical color image features. This is mostly because of the fact that a traditional image is a two-dimensional projection of the real world. In contrast, light field imaging makes available ...

International Society for Optics and Photonics2014

Positivity for Kac polynomials and DT-invariants of quivers

Tamás Hausel

We give a cohomological interpretation of both the Kac polynomial and the refined Donaldson-Thomas-invariants of quivers. This interpretation yields a proof of a conjecture of Kac from 1982 and gives a new perspective on recent work of Kontsevich Soibelman ...

Annal Mathematics2013

Encoding and decoding of generalized Reed-Solomon codes using parallel processing techniques

Mohammad Amin Shokrollahi

A system, computer program, and/or method for encoding data that can correct r/2 errors. The original symbols are transformed using a Fourier transform of length p. Generator polynomials are used to encode the p blocks separately, and an inverse Fourier tr ...

2012

Zero-crossing approach to high-resolution reconstruction in frequency-domain optical-coherence tomography

Theo Lasser, Marcel Leutenegger, Chandra Sekhar Seelamantula, Arno Pino Bouwens

We address the problem of high-resolution reconstruction in frequency-domain optical-coherence tomography (FDOCT). The traditional method employed uses the inverse discrete Fourier transform, which is limited in resolution due to the Heisenberg uncertainty ...

2012

Logarithmic Transformation Technique for Exact Signal Recovery in Frequency-Domain Optical-Coherence Tomography

Michaël Unser

We address the problem of exact signal recovery in frequency-domain optical-coherence tomography (FDOCT). The standard technique for tomogram reconstruction is the inverse Fourier transform. However, the inverse Fourier transform is known to yield autocorr ...

SPIE2007