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Related papers: Time Dilation and Quasar Variability

200 papers

A class of methods for measuring time delays between astronomical time series is introduced in the context of quasar reverberation mapping, which is based on measures of randomness or complexity of the data. Several distinct statistical…

Instrumentation and Methods for Astrophysics · Physics 2017-08-16 Doron Chelouche , Francisco Pozo Nuñez , Shay Zucker

Scalar field dark matter offers an interesting alternative to the traditional WIMP dark matter picture. Astrophysical and cosmological simulations are useful to constraining the mass of the dark matter particle in this model. This is…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-13 Andrew Eberhardt , Alvaro Zamora , Michael Kopp , Tom Abel

We find statistically significant correlations in the cosmological matter power spectrum over the full range of observable scales. While the correlations between individual modes are weak, the band-averaged power spectrum shows strong…

Astrophysics · Physics 2009-10-31 A. Meiksin , Martin White

Aims: Establish the dependence of variability properties, such as characteristic timescales and variability amplitude, on basic quasar parameters such as black hole mass and accretion rate, controlling for the rest-frame wavelength of…

Astrophysics of Galaxies · Physics 2023-11-21 P. Arevalo , E. Churazov , P. Lira , P. Sanchez-Saez , S. Bernal , L. Hernandez-Garcia , E. Lopez-Navas , P. Patel

In order to respect the Principle of Relativity, the analysis of the behavior of the longitudinal light clock reveals the necessity to extend the Doppler effect also to space and time. As a consequence, the bodies in inertial motion must…

General Physics · Physics 2015-11-16 Giovanni Zanella

The experimental proofs of strong time invariance violation in optics are discussed. Time noninvariance is the only real physical base for explanation the origin of the most phenomena in nonlinear optics. The experimental study of forward…

General Physics · Physics 2007-05-23 V. A. Kuz'menko

We consider the multiple scattering of a scalar wave in a disordered medium with a weak nonlinearity of Kerr type. The perturbation theory, developed to calculate the temporal autocorrelation function of scattered wave, fails at short…

Disordered Systems and Neural Networks · Physics 2016-08-31 S. E. Skipetrov

Cosmic observations strongly support a time varying scenario for matter/space. On the other hand, so far, observations at solar system scale failed to identify any time variation on matter/space characteristics. To explain both results it…

Astrophysics · Physics 2007-05-23 Alfredo Gouveia Oliveira , Rodrigo de Abreu

In quantum mechanics the time dimension is treated as a parameter, while the three space dimensions are treated as observables. This assumption is both untested and inconsistent with relativity. From dimensional analysis, we expect quantum…

Quantum Physics · Physics 2019-05-27 John Ashmead

The lifetime t_Q of the luminous phase of quasars is constrained by current observations to be between 10^6 and 10^8 years, but is otherwise unkown. We model the quasar luminosity function in detail in the optical and X-ray bands using the…

Astrophysics · Physics 2014-10-13 Zoltan Haiman , Lam Hui

We examine the dependence of the spatial two-point correlation function of quasars $\xi_{qq}(r,z)$ at different redshifts on the initial power spectrum in flat cosmological models. Quasars and other elements of the large-scale structure of…

Astrophysics · Physics 2007-05-23 B. Novosyadlyj , Yu. Chornij

The "theoretical limit of time-frequency resolution in Fourier analysis" is thought to originate in certain mathematical and/or physical limitations. This, however, is not true. The actual origin arises from the numerical (technical) method…

Physics and Society · Physics 2025-03-28 Fumihiko Ishiyama

We consider a simple model, based on currently accepted models for active galactic nuclei, for a quasi-stellar object (QSO or ``quasar'') and examine the influence that correlation- induced spectral changes (``The Wolf Effect'') may have…

Astrophysics · Physics 2009-10-30 Daniel F. V. James

Quantum fluctuations in spacetime can, in some cases, lead to distortion in astronomical images of faraway objects. In particular, a stochastic model of quantum gravity predicts an accumulated fluctuation in the path length $\Delta L$ with…

General Relativity and Quantum Cosmology · Physics 2024-05-24 Vincent S. H. Lee , Kathryn M. Zurek , Yanbei Chen

Endeavours of the unification of the four fundamental interactions have resulted in a development of theories having cosmological solutions in which low-energy limits of fundamental physical constants vary with time. The validity of such…

Astrophysics · Physics 2011-05-23 A. V. Ivanchik , A. Y. Potekhin , D. A. Varshalovich

Spectral features absorbed against some radio quasars exhibit ~50mJy variations, with the lines varying both relative to the continuum and, when several lines are present, even relative to one another. We point out that such variability can…

Astrophysics · Physics 2009-11-10 Jean-Pierre Macquart

The space-time metric is widely believed to be subject to stochastic fluctuations induced by quantum gravity at the Planck scale. This work is based on two different phenomenological approaches being currently made to this topic, and…

Astrophysics · Physics 2009-11-07 R. Le Gallou

The time delay between images of strongly gravitationally lensed quasars is an established cosmological probe. Its limitations, however, include uncertainties in the assumed mass distribution of the lens. We re-examine the methodology of a…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-17 Angela L. H. Ng

Using Fermat's principle, we analyze the effects of very long wavelength gravitational waves upon the images of a gravitationally lensed quasar. We show that the lens equation in the presence of gravity waves is equivalent to that of a lens…

Astrophysics · Physics 2011-09-09 J. Frieman , D. Harari , G. Surpi

We show that apparently conflicting results on the time-variation of the measured Cl-36 decay rates can be readily understood as arising from solar variability beyond the simple Earth-Sun distance model, and hence are not an indication of…