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Modern radar systems are designed to have high Doppler tolerance to detect fast-moving targets. This means range and Doppler estimations are inevitably coupled, opening pathways to concealing objects by imprinting artificial Doppler…

Signal Processing · Electrical Eng. & Systems 2023-05-17 V. Kozlov , D. Vovchuk , P. Ginzburg

This article is motivated by the observation, that calculations of the Unruh effect based on idealized particle detectors are usually made in a way that involves integrations along the {\em entire} detector trajectory up to the infinitely…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Sebastian Schlicht

Building on the well-known Unruh-Davies effect, we examine the effects of projective measurements and quantum communications between accelerated and stationary observers. We find that the projective measurement by a uniformly accelerated…

Quantum Physics · Physics 2009-11-16 Muxin Han , S. Jay Olson , Jonathan P. Dowling

We explored the motion of test particles near slowly rotating relativistic star having a uniform luminosity. In order to derive the test particle's equations of motion, we made use of the radiation stress-energy tensor first constructed by…

High Energy Astrophysical Phenomena · Physics 2010-04-14 Jae-Sok Oh , Hongsu Kim , Hyung Mok Lee

We establish oracle inequalities for a version of the Lasso in high-dimensional fixed effects dynamic panel data models. The inequalities are valid for the coefficients of the dynamic and exogenous regressors. Separate oracle inequalities…

Statistics Theory · Mathematics 2016-01-05 Anders Bredahl Kock , Haihan Tang

In a seminal paper, Unruh and Wald found that the detection of a right Rindler particle by a linearly uniformly accelerated detector coupled to a Klein-Gordon field in the Minkowski vacuum leads to the creation of a Minkowski particle from…

General Relativity and Quantum Cosmology · Physics 2023-07-19 Angel Garcia-Chung , Benito A. Juárez-Aubry , Daniel Sudarsky

We examine the behavior of the variable Eddington factor for a relativistically moving radiative flow in the vertical direction. We adopt the "one-tau photo-oval" approximation in the comoving frame. Namely, the comoving observer sees…

High Energy Astrophysical Phenomena · Physics 2015-05-13 J. Fukue

In this paper we investigate the three-dimensional (3D) motion of a test particle in a stationary, axially symmetric spacetime around a central compact object, under the influence of a radiation field. To this aim we extend the…

General Relativity and Quantum Cosmology · Physics 2019-11-05 Vittorio De Falco , Pavel Bakala , Emmanuele Battista , Debora Lančová , Maurizio Falanga , Luigi Stella

This paper discusses the Doppler effect for radiation emitted by a relativistic oscillator in vacuum described geometrically as an ellipsoid in momentum space. Spectral and angular properties of the Doppler X-ray radiation emitted by a…

Accelerator Physics · Physics 2025-03-06 A. Shchagin , G. Kube , A. Potylitsyn , S. Strokov

Formal definition of the reference frame is given. This definition is valid for nonrelativistic and relativistic cases. Proposed definition allows using wide classes of reference frames without restriction to inertial, uniformly accelerated…

Classical Physics · Physics 2014-03-10 Oleg Igorevich Drivotin

In this paper, we investigate how a uniformly accelerated detector responds to vacuum state of a Dirac field in the $\kappa$-Minkowski space-time. Starting from $\kappa$-deformed Dirac theory, which is invariant under $\kappa$-Poincare…

High Energy Physics - Theory · Physics 2013-05-13 E. Harikumar , Ravikant Verma

The acceleration transformations form a 4-parameter Abelian subgroup of the conformal group of Minkowski spacetime. The passive interpretation of acceleration transformations leads to a congruence of uniformly accelerated observers in…

General Relativity and Quantum Cosmology · Physics 2019-08-05 Bahram Mashhoon

We study how the entanglement of an entangled pair of particles is affected when one or both of the pair is uniformly accelerated, while the detector remains in an inertial frame. We find that the entanglement is unchanged if all degrees of…

Quantum Physics · Physics 2007-09-11 W. L. Ku , M. -C. Chu

The Rotational Doppler Effect (RDE) involves both the orbital angular momentum of electromagnetic radiation as well as its helicity. The RDE phenomena associated with photon helicity go beyond the standard theory of relativity. The purpose…

General Relativity and Quantum Cosmology · Physics 2024-03-27 Bahram Mashhoon

Radar-based respiratory measurement is a promising tool for the noncontact detection of sleep apnea. Our team has reported that apnea events can be accurately detected using the statistical characteristics of the amplitude of respiratory…

Signal Processing · Electrical Eng. & Systems 2025-05-27 Kodai Hasegawa , Shigeaki Okumura , Hirofumi Taki , Hironobu Sunadome , Satoshi Hamada , Susumu Sato , Kazuo Chin , Takuya Sakamoto

In this work we consider the spontaneous symmetry breaking of the electroweak $SU(2)_L\times U(1)_Y$ gauge group into $U(1)_{em}$ taken place in the Standard Model of particle physics as seen from the point of view of an accelerating…

General Relativity and Quantum Cosmology · Physics 2017-11-22 Antonio Dobado

A local criteria for the existence of an accelerated frame of reference is found. An accelerated frame of reference could exist in all regions where a non-null (non-isotropic) vector field does not degenerate in a null (isotropic) vector…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Sawa Manoff

This paper presents three non-linear observers on three examples of engineering interest: a chemical reactor, a non-holonomic car, and an inertial navigation system. For each example, the design is based on physical symmetries. This…

Optimization and Control · Mathematics 2016-11-17 S. Bonnabel , Ph. Martin , P. Rouchon

In this note, we propose that an object moving with proper constant acceleration, i.e., a Rindler observer experiences a sublimation (or evaporation) process. In this first proposal, we do not consider the backreaction due to the…

General Relativity and Quantum Cosmology · Physics 2020-10-08 J. A. Rosabal

We give an interpretation of the temperature in de Sitter universe in terms of a dynamical Unruh effect associated with the Hubble sphere. As with the quantum noise perceived by a uniformly accelerated observer in static space-times,…

General Relativity and Quantum Cosmology · Physics 2011-09-23 R. Casadio , S. Chiodini , A. Orlandi , G. Acquaviva , R. Di Criscienzo , L. Vanzo