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The fine structure constant, $\alpha$, sets the strength of the electromagnetic force. The Standard Model of particle physics provides no explanation for its value, which could potentially vary. The wavelengths of stellar absorption lines…

太阳与恒星天体物理 · 物理学 2022-11-30 Michael T. Murphy , Daniel A. Berke , Fan Liu , Chris Flynn , Christian Lehmann , Vladimir A. Dzuba , Victor V. Flambaum

We report a new constraint on the variation of the fine-structure constant based on the analysis of 15 Si IV doublets selected from a ESO-UVES sample. We find \Delta\alpha/\alpha = (+0.15+/-0.43) x 10^-5 over a redshift range of 1.59< z <…

天体物理学 · 物理学 2009-11-10 Hum Chand , Patrick Petitjean , Raghunathan Srianand , Bastien Aracil

We test the consistency of several independent astrophysical measurements of fundamental dimensionless constants. In particular, we compare direct measurements of the fine-structure constant $\alpha$ and the proton-to-electron mass ratio…

宇宙学与河外天体物理 · 物理学 2014-05-05 M. C. Ferreira , O. Frigola , C. J. A. P. Martins , A. M. R. V. L. Monteiro , J. Solà

Sun-like stars are a new probe of variations in the fine-structure constant, $\alpha$, via the solar twins approach: velocity separations of close pairs of absorption lines are compared between stars with very similar stellar parameters,…

太阳与恒星天体物理 · 物理学 2023-01-04 Daniel A. Berke , Michael T. Murphy , Chris Flynn , Fan Liu

The use of nonstandard methods to characterize properties of weak, strong and mixed extensions of congruences to ultrafilters has been the main topic of several recent papers. We show that similar methods can be used to characterize the…

It has been pointed out by Shlyakhter that data from the natural fission reactors which operated about two billion years ago at Oklo (Gabon) had the potential of providing an extremely tight bound on the variability of the fine-structure…

高能物理 - 唯象学 · 物理学 2016-09-06 Thibault Damour , Freeman Dyson

We provide an analytical argument for understanding the likely nature of parameter shifts between those coming from an analysis of a dataset and from a subset of that dataset, assuming differences are down to noise and any intrinsic…

天体物理仪器与方法 · 物理学 2020-10-28 Steven Gratton , Anthony Challinor

The scaling behaviour of the diffraction intensity near the origin is investigated for (partially) ordered systems, with an emphasis on illustrative, rigorous results. This is an established method to detect and quantify the fluctuation…

度量几何 · 数学 2021-06-15 Michael Baake , Uwe Grimm

A frequentist definition of sensitivity of a search for new phenomena is discussed, that has several useful properties. It is based on completely standard concepts, is generally applicable, and has a very clear interpretation. It is…

数据分析、统计与概率 · 物理学 2007-05-23 Giovanni Punzi

A new thresholding method, based on L-statistics and called order thresholding, is proposed as a technique for improving the power when testing against high-dimensional alternatives. The new method allows great flexibility in the choice of…

统计理论 · 数学 2010-10-21 Min Hee Kim , Michael G. Akritas

With the recognition that fast flavor instabilities likely affect supernova and neutron-star-merger neutrinos, using simulation data to pin down when and where the instabilities occur has become a high priority. The effort faces an…

高能物理 - 唯象学 · 物理学 2021-06-23 Lucas Johns , Hiroki Nagakura

A new weak measurement procedure is introduced for finite samples which yields accurate weak values that are outside the range of eigenvalues and which do not require an exponentially rare ensemble. This procedure provides a unique…

量子物理 · 物理学 2009-11-13 Jeff Tollaksen

This article reviews the two major recent developments that significantly improved cosmological measurements of fundamental constants derived from high resolution quasar spectroscopy. The first one is the deployment of astronomical Laser…

宇宙学与河外天体物理 · 物理学 2023-01-20 Dinko Milaković , Chung-Chi Lee , Paolo Molaro , John K. Webb

In Nuclear Physics numerous possibilities exist to investigate fundamental symmetries and interactions. In particular, the precise measurements of properties of fundamental fermions, searches for new interactions in $\beta$-decays, and…

核实验 · 物理学 2014-11-18 Klaus P. Jungmann

The data from the QSO absorption lines indicating a nonzero time-variability of the fine-structure constant has been re-analyzed on the basis of a "damped-oscillator" fit, as motivated by the same type of behavior of a scalar field,…

天体物理学 · 物理学 2015-06-24 Yasunori Fujii

Determinations of alpha_s are reviewed. Current results are limited to a precision of around 3-20%, largely by theoretical uncertainties. All measurements are consistent with a `world average' value of 0.118 +- 0.005 and there is no…

高能物理 - 实验 · 物理学 2011-07-19 P. N. Burrows

Within the context of mass-varying neutrinos, we construct a cosmological model that has a phase transition in the electromagnetic fine structure constant \alpha at a redshift of 0.5. The model accommodates hints of a time variable \alpha…

高能物理 - 唯象学 · 物理学 2008-11-26 L. Anchordoqui , V. Barger , H. Goldberg , D. Marfatia

We review properties of cosmological theories for the variation of the fine structure 'constant'. We highlight some general features of the cosmological models that exist in these theories with reference to recent quasar data that are…

广义相对论与量子宇宙学 · 物理学 2012-12-11 John D. Barrow

Cosmology contributes a good deal to the investigation of variation of fundamental physical constants. High resolution data is available and allows for detailed analysis over cosmological distances and a multitude of methods were developed.…

宇宙学与河外天体物理 · 物理学 2009-10-28 M. Wendt , D. Reimers , P. Molaro

The Fast Fourier Transform (FFT) is a fundamental tool for signal analysis, widely used across various fields. However, traditional FFT methods encounter challenges in adjusting the frequency bin interval, which may impede accurate spectral…

数据结构与算法 · 计算机科学 2024-03-27 Haichao Xu