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The rapid variability of the VHE emission reported for some TeV blazars implies Doppler factors well in excess of those inferred from superluminal motions and unification schemes. We propose that those extreme flares may result from…

Astrophysics · Physics 2009-11-13 Amir Levinson

As it has become common to use many computer cores in routine applications, finding good ways to parallelize popular algorithms has become increasingly important. In this paper, we present a parallelization scheme for Markov chain Monte…

Methodology · Statistics 2016-06-01 Guillaume W. Basse , Natesh S. Pillai , Aaron Smith

Atomistic simulations provide valuable insights into the physical processes governing material behavior. However, their applicability is fundamentally constrained by the limited time scales accessible to brute-force simulations. This…

Computational Physics · Physics 2026-02-16 Michael Kim , Wei Cai

Blazars' non-thermal emission shows rapid variability across all wavelengths, so spectral energy distributions (SEDs) built from quasi-simultaneous data are crucial for revealing the jets physical properties. In this work, we construct…

High Energy Astrophysical Phenomena · Physics 2026-05-22 Yi Zhong , Zhujian Wan , Rui Xue , Hubing Xiao , Dingrong Xiong , Ze-Rui Wang

We introduce a new method to simulate the physics of rare events. The method, an extension of the Temperature Accelerated Molecular Dynamics, comes in use when the collective variables introduced to characterize the rare events are either…

Computational Physics · Physics 2017-09-13 Giovanni Ciccotti , Simone Meloni

Aim : The nearby TeV blazar 1ES 1959+650 (z=0.047) was reported to be in flaring state during June - July 2016 by Fermi-LAT, FACT, MAGIC and VERITAS collaborations. We studied the spectral energy distributions (SEDs) in different states of…

High Energy Astrophysical Phenomena · Physics 2018-03-21 S. R. Patel , A. Shukla , V. R. Chitnis , D. Dorner , K. Mannheim , B. S. Acharya , B. J. Nagare

TeV-emitting BL Lac type blazars represent the extreme end of the blazar population. They are characterized by relatively weak jets and radiatively inefficient accretion disks. Particles accelerated in these jets experience fewer radiative…

High Energy Astrophysical Phenomena · Physics 2025-08-14 Cassidy Metzger , Andrea Gokus , Manel Errando

The broad-band spectral distributions of non-thermal sources, such as those of several known blazars, are well described by a log-parabolic fit. The second degree term in these fits measures the curvature in the spectrum. In this paper we…

High Energy Astrophysical Phenomena · Physics 2015-05-28 A. Tramacere , E. Massaro , A. M. Taylor

We present the Local Self-Balancing sampler (LSB), a local Markov Chain Monte Carlo (MCMC) method for sampling in purely discrete domains, which is able to autonomously adapt to the target distribution and to reduce the number of target…

Artificial Intelligence · Computer Science 2022-07-06 Emanuele Sansone

The very high energy (VHE) gamma-ray spectral indices of blazars show strong correlation with the source redshift. Absence of any such correlation in low energy gamma rays and X-rays indicate the presence of Extragalactic Background Light…

High Energy Astrophysical Phenomena · Physics 2022-02-23 Malik Zahoor , Sunder Sahayanathan , Shah Zahir , Naseer Iqbal , Aaqib Manzoor , Nilay Bhatt

We propose a new mechanism for the prompt emission of gamma-ray burst. In our model electrons are continuously accelerated in the post shock region via plasma turbulence. Using the Monte Carlo technique, we mimic the second-order Fermi…

High Energy Astrophysical Phenomena · Physics 2009-11-05 K. Asano , T. Terasawa

The double humped SED (Spectral Energy Distribution) of blazars, and their flaring phenomena can be explained by various leptonic and hadronic models. However, accurate modeling of the high frequency component and clear identification of…

Astrophysics · Physics 2011-11-10 B. Behera , S. J. Wagner

We present a new time-dependent inhomogeneous jet model of non-thermal blazar emission, which reproduces the entire spectral energy distribution together with the rapid gamma-ray variability. Ultra-relativistic leptons are injected at the…

Astrophysics · Physics 2011-02-11 Timothé Boutelier , Gilles Henri , Pierre-Olivier Petrucci

Current Cherenkov telescopes have identified a population of ultra-high-frequency peaked BL Lac objects (UHBLs), also known as extreme blazars, that exhibit exceptionally hard TeV spectra, including 1ES 0229+200, 1ES 0347-121, RGB…

High Energy Astrophysical Phenomena · Physics 2015-02-13 M. Cerruti , A. Zech , C. Boisson , S. Inoue

We summarize broadband observations of the TeV-emitting blazar 1ES 1959+650, including optical R-band observations by the robotic telescopes Super-LOTIS and iTelescope, UV observations by Swift UVOT, X-ray observations by the Swift X-ray…

Markov chain Monte Carlo (MCMC) algorithms are used to estimate features of interest of a distribution. The Monte Carlo error in estimation has an asymptotic normal distribution whose multivariate nature has so far been ignored in the MCMC…

Statistics Theory · Mathematics 2016-07-05 Dootika Vats , James M. Flegal , Galin L. Jones

Context. The intrinsic TeV emission of some BL Lacs are characterized by a hard spectrum (the hard-TeV spectrum) after correcting for the extragalactic background light. The hard-TeV spectra pose a challenge to conventional one-zone models,…

High Energy Astrophysical Phenomena · Physics 2022-03-30 Wei-Jian Li , Rui Xue , Guang-Bo Long , Ze-Rui Wang , Shigehiro Nagataki , Da-Hai Yan , Jian-Cheng Wang

We propose a new model for the description of ultra-short flares from TeV blazars by compact magnetized condensations (blobs), produced when red giant stars cross the jet close to the central black hole. Our study includes a simple…

High Energy Astrophysical Phenomena · Physics 2015-05-20 Maxim V. Barkov , Felix A. Aharonian , Sergey V. Bogovalov , Stanislav R. Kelner , Dmitriy V. Khangulyan

Sampling the three-dimensional (3D) spin glass -- i.e., generating equilibrium configurations of a 3D lattice with quenched random couplings -- is widely regarded as one of the central and long-standing open problems in statistical physics.…

Statistical Mechanics · Physics 2025-09-30 Tao Chen , Jing Liu , Youjin Deng , Pan Zhang

We present a fully analytical, time-dependent leptonic one-zone model that describes a simplified radiation process of multiple interacting ultrarelativistic electron populations, accounting for the flaring of GeV blazars. In this model,…

High Energy Astrophysical Phenomena · Physics 2018-09-05 Christian Röken , Florian Schuppan , Katharina Proksch , Sebastian Schöneberg