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We calculate the spectrum of blast wave models of gamma-ray burst sources, for various assumptions about the magnetic field density and the relativistic particle acceleration efficiency. For a range of physically plausible models we find…

Astrophysics · Physics 2011-09-30 P. Meszaros , M. J. Rees , H. Papathanassiou

We propose a Bayesian approach to the problem of multi-reference alignment -- the recovery of signals from noisy, randomly shifted observations. While existing frequentist methods accurately recover the signal at arbitrarily low…

Signal Processing · Electrical Eng. & Systems 2025-10-15 Axel Janson , Joakim Andén

Searches for gravitational-wave bursts (transient signals, typically of unknown waveform) require identification of weak signals in background detector noise. The sensitivity of such searches is often critically limited by non-Gaussian…

General Relativity and Quantum Cosmology · Physics 2013-10-02 Thomas S. Adams , Duncan Meacher , James Clark , Patrick J. Sutton , Gareth Jones , Ariana Minot

Gamma ray bursts are excellent candidates to constrain physical models which break Lorentz symmetry. We consider deformed dispersion relations which break the boost invariance and lead to an energy-dependent speed of light. In these models,…

Astrophysics · Physics 2009-11-11 Maria Rodriguez Martinez , Tsvi Piran

High-energy photons of gamma-ray bursts (GRBs) might be emitted at different intrinsic times with energy dependence at the source. In this letter, we expand the model from previous works on testing the Lorentz Invariance Violation (LV) with…

High Energy Astrophysical Phenomena · Physics 2024-09-13 Hanlin Song , Bo-Qiang Ma

We use extreme-ultraviolet interferometry to measure the phase of high-order harmonic generation from transiently aligned CO2 molecules. We unambiguously observe a reversal in phase of the high order harmonic emission for higher harmonic…

Atomic Physics · Physics 2009-11-13 Xibin Zhou , Robynne Lock , Wen Li , Nick Wagner , Margaret. M. Murnane , Henry C. Kapteyn

Inverse Problem techniques offer powerful tools which deal naturally with marginal data and asymmetric or strongly smoothing kernels, in cases where parameter-fitting methods may be used only with some caution. Although they are typically…

Astrophysics · Physics 2007-05-23 Norman Gray , Iain J. Coleman

Mixture models with Gamma and or inverse-Gamma distributed mixture components are useful for medical image tissue segmentation or as post-hoc models for regression coefficients obtained from linear regression within a Generalised Linear…

Machine Learning · Statistics 2016-07-27 A. Llera , D. Vidaurre , R. H. R. Pruim , C. F. Beckmann

We present a methodology for automated real-time analysis of a radio image data stream with the goal to find transient sources. Contrary to previous works, the transients we are interested in occur on a time-scale where dispersion starts to…

Instrumentation and Methods for Astrophysics · Physics 2021-08-09 David Ruhe , Mark Kuiack , Antonia Rowlinson , Ralph Wijers , Patrick Forré

In particle physics, as in many areas of science, parameter inference relies on simulations to bridge the gap between theory and experiment. Recent developments in simulation-based inference have boosted the sensitivity of analyses;…

High Energy Physics - Phenomenology · Physics 2026-04-23 Ezequiel Alvarez , Sean Benevedes , Manuel Szewc , Jesse Thaler

With the advent of high repetition rate laser facilities, novel diagnostic tools compatible with these advanced specifications are required. This paper presents the design of an active gamma-ray spectrometer intended for these high…

Given a set of samples, a few of them being possibly saturated, we propose an efficient algorithm in order to cancel saturation while reconstructing band-limited signals. Our method satisfies a minimum-loss constraint and relies on…

Signal Processing · Electrical Eng. & Systems 2018-09-20 Kyong Hwan Jin , Gain Kim , Yusuf Leblebici , Jong Chul Ye , Michael Unser

The Burst and Transient Source Experiment (BATSE), aboard the Compton Gamma Ray Observatory (CGRO), provided a record of the low-energy gamma-ray sky (20-1000 keV) between 1991 April and 2000 May (9.1y). Using the Earth Occultation…

We consider a density estimation problem arising in nuclear physics. Gamma photons are impinging on a semiconductor detector, producing pulses of current. The integral of this pulse is equal to the total amount of charge created by the…

Statistics Theory · Mathematics 2007-06-13 Eric Moulines , Francois Roueff , Antoine Souloumiac , Thomas Trigano

In a mixed generalized linear model, the goal is to learn multiple signals from unlabeled observations: each sample comes from exactly one signal, but it is not known which one. We consider the prototypical problem of estimating two…

Statistics Theory · Mathematics 2026-01-12 Yihan Zhang , Marco Mondelli , Ramji Venkataramanan

We describe the strong spectral evolution that occurs during a gamma-ray burst pulse and the means by which it can be analyzed. Based on observed empirical correlations, an analytical model is constructed which is used to describe the pulse…

Astrophysics · Physics 2009-11-10 Felix Ryde

Perturbation theory of large-scale structures of the Universe at next-to-leading order and next-to-next-to-leading order provides us with predictions of cosmological statistics at sub-percent level in the mildly non-linear regime. Its use…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-08 Ken Osato , Takahiro Nishimichi , Atsushi Taruya , Francis Bernardeau

We study the inverse problem of locating point sources from far-field data under plane wave incidence. A direct computational method is developed based on multiple scattering theory, using a novel indicator function to avoid iterative…

Analysis of PDEs · Mathematics 2025-09-18 Nana Meng

The prompt emission of the gamma-ray bursts is found to be very energetic, releasing ~10^51 ergs in a flash. However, their emission mechanism remains unclear and understanding their spectra is a key to determining the emission mechanism.…

Astrophysics · Physics 2015-06-24 Y. Kaneko , R. D. Preece , M. M. Gonzalez , B. L. Dingus , M. S. Briggs

While Gamma Ray Bursts (GRBs) have the potential to shed light on the astrophysics of jets, compact objects, and cosmology, a major set back in their use as probes of these phenomena stems from our incomplete knowledge surrounding their…

High Energy Astrophysical Phenomena · Physics 2024-08-12 Tyler Parsotan , Davide Lazzati