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Accreting black holes and neutron stars in their hard (low) state show not only very similar X/gamma-ray spectra but also that the behaviour of their light curves is quite similar which can be quantified as having similar power-density…

Astrophysics · Physics 2010-12-13 Juri Poutanen

We examine the effects of the linear and the cosmological redshift-space distortions on the power spectrum of cosmological objects on a light cone. We develop theoretical formulae for the power spectrum in linear theory of density…

Astrophysics · Physics 2009-10-31 Hiroaki Nishioka , Kazuhiro Yamamoto

The concept of weak invariants has recently been introduced in the context of conserved quantities in finite-time processes in nonequilibrium quantum thermodynamics. A weak invariant itself has a time-dependent spectrum, but its expectation…

Quantum Physics · Physics 2020-06-11 Sumiyoshi Abe

Quantum mechanics rests on the assumption that time is a classical variable. As such, classical time is assumed to be measurable with infinite accuracy. However, all real clocks are subject to quantum fluctuations, which leads to the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 J. M. Isidro , J. L. Gonzalez-Santander , P. Fernandez de Cordoba

Inspired by the observation of a distributed time delay in the nonlinear response of an optical resonator, we investigate the effects of a similar delay on a noise-driven mechanical oscillator. For a delay time that is commensurate with the…

Optics · Physics 2022-02-16 K. J. H. Peters , S. R. K. Rodriguez

The principle of invariance of the velocity of light is only valid for the wrong measurements of inertial observers who ignore their own movement and consider themselves at rest. The Langevin (or clock) paradox arises when it is assumed…

Classical Physics · Physics 2008-03-17 A. Lopez-Ramos

(Abridged) Several phenomena in astrophysics generate light curves with time delays. Among these are reverberation mapping, and lensed quasars. In some systems, the measurement of the time-delay is complicated by the fact that the delayed…

Instrumentation and Methods for Astrophysics · Physics 2021-07-14 Ofer M. Springer , Eran O. Ofek

We analyze the properties of quasar variability using repeated SDSS imaging data in five UV-to-far red photometric bands, accurate to 0.02 mag, for 13,000 spectroscopically confirmed quasars. The observed time lags span the range from 3…

In this talk we discuss the effect upon the di-proton, di-neutron and deuteron of a time variation of the QCD gauge coupling. We describe how a time evolution of the size of extra dimensions can give rise to such a variation and show how…

High Energy Physics - Phenomenology · Physics 2007-05-23 Malcolm Fairbairn

We use numerical simulations to test a broad range of plausible observational strategies designed to measure the time delay between the images of gravitationally lensed quasars. Artificial quasar light curves are created along with…

Astrophysics · Physics 2009-11-10 A. Eigenbrod , F. Courbin , C. Vuissoz , G. Meylan , P. Saha , S. Dye

An attempt is made to explain time non-dilation allegedly observed in quasar light curves. The explanation is based on the assumption that quasar black holes are, in some sense, foreign for our Friedmann-Robertson-Walker universe and do not…

General Relativity and Quantum Cosmology · Physics 2015-10-02 O. I. Chashchina , Z. K. Silagadze

A rigorous quantum relativistic approach has been used to calculate the relationship between the decay laws of an unstable particle seen from two inertial frames moving with respect to each other. In agreement with experiment, it is found…

General Physics · Physics 2007-05-23 Eugene V. Stefanovich

A curious effect is uncovered by calculating the it time evolving probability of reflection of a Gaussian wave packet from a rectangular potential barrier while it is perturbed by reducing its height. A time interval is found during which…

Quantum Physics · Physics 2009-11-07 S. Bandyopadhyay , A. S. Majumdar , D. Home

It has been known that dimensional constants such as $\hbar$, $c$, $G$, $e$, and $k$ are merely human constructs whose values and units vary depending on the chosen system of measurement. Therefore, the time variation of dimensional…

General Physics · Physics 2024-06-06 Seokcheon Lee

Astrophysical indications that the fine structure constant has undergone a small time variation during the cosmological evolution are discussed within the framework of the standard model of the electroweak and strong interactions and of…

High Energy Physics - Phenomenology · Physics 2007-05-23 H. Fritzsch

We determine the variability-luminosity relationship of quasars and Seyfert galaxies in the rest frame of the objects using IUE spectra. We find that the variability decreases with the luminosity. An important part of the scatter in the…

Astrophysics · Physics 2007-05-23 Stephane Paltani , Thierry J. -L. Courvoisier

The relationship between variability, luminosity and redshift in the South Galactic Pole QSO sample is examined in an effort to disentangle the effects of luminosity and redshift in the amplitude of the optical variations. The…

Astrophysics · Physics 2015-06-24 R. Cid Fernandes , I. Aretxaga , R. Terlevich

The stochastic photometric variability of quasars is known to follow a random-walk phenomenology on emission timescales of months to years. Some high-cadence restframe optical monitoring in the past has hinted at a suppression of…

Astrophysics of Galaxies · Physics 2024-11-13 Ji-Jia Tang , Christian Wolf , John Tonry

The light scattered by an extrasolar Earth-like planet's surface and atmosphere will vary in intensity and color as the planet rotates; the resulting light curve will contain information about the planet's properties. Since most of the…

Astrophysics · Physics 2007-05-23 Eric B. Ford , Sara Seager , Edwin L. Turner

The cosmic time dilation observed in Type Ia supernova light curves suggests that the passage of cosmic time varies throughout the evolution of the Universe. This observation implies that the rate of proper time is not constant, as assumed…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-25 Vaclav Vavrycuk
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