English
Related papers

Related papers: Re/Os constraint on the time-variability of the fi…

200 papers

Astrophysical observations indicate a time variation of the proton-electron mass ratio and of the fine-structure constant. We discuss this phenomenon in models of Grand Unification. In these models a time variation of the fine-structure…

Astrophysics · Physics 2010-12-17 Xavier Calmet , Harald Fritzsch

Recent updated results of quasar spectra suggested a 3.9$\sigma$ significance of spatial variation of the fine-structure constant. Theoretically, it is important to examine whether the fine-structure constant, as a fundamental constant in…

General Relativity and Quantum Cosmology · Physics 2020-11-17 Zhe Chang , Qing-Hua Zhu

We discuss how existing astrophysical measurements of various combinations of the fine-structure constant $\alpha$, the proton-to-electron mass ratio $\mu$ and the proton gyromagnetic ratio g$_{p}$ towards the radio source PKS1413+135 can…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-01 A. M. R. V. L. Monteiro , M. C. Ferreira , M. D. Julião , C. J. A. P. Martins

We study ultranarrow $5s_{1/2}$ - $4f_{5/2}$ transitions in Nd$^{13+}$ and Sm$^{15+}$ and demonstrate that they lie in the optical region. The transitions are insensitive to external perturbations. At the same time they are sensitive to the…

Atomic Physics · Physics 2015-06-11 V. A. Dzuba , A. Derevianko , V. V. Flambaum

We revisit QCD sum rules for the decay constants of heavy-light mesons. In the sum rules for the vector mesons B^*_(s) and D^*_(s) we improve the accuracy of OPE, taking into account the O(alpha_s^2) terms in the perturbative part and…

High Energy Physics - Phenomenology · Physics 2015-03-30 Patrick Gelhausen , Alexander Khodjamirian , Alexei A. Pivovarov , Denis Rosenthal

We study the time variability of five Fe Low ionization Broad Absorption Line (FeLoBAL) QSOs using repeated spectroscopic observations with the 2m telescope at IUCAA Girawali observatory (IGO) spanning an interval of upto 10 years. We…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 M. Vivek , R. Srianand , P. Petitjean , P. Noterdaeme , V. Mohan , A. Mahabal , V. C. Kuriakose

The color-octet (CO) mechanism is a cornerstone of non-relativistic QCD, yet its long-distance matrix elements remain limited, preventing stringent tests of the theory. We demonstrate that the Artru-Collins asymmetry in hadronic decays of…

High Energy Physics - Phenomenology · Physics 2026-03-20 Zhi-Guo He , Guanghui Li , Yu-Jie Tian , Xin-Kai Wen , Bin Yan

Recent measurements of a peak in the angular power spectrum of the cosmic microwave background appear to suggest that geometry of the universe is close to being flat. But if other accepted indicators of cosmological parameters are also…

Astrophysics · Physics 2009-10-31 R. A. Battye , R. Crittenden , J. Weller

The comparison of different atomic transition frequencies over time can be used to determine the present value of the temporal derivative of the fine structure constant alpha in a model-independent way without assumptions on constancy or…

Atomic Physics · Physics 2009-11-10 E. Peik , B. Lipphardt , H. Schnatz , T. Schneider , Chr. Tamm , S. G. Karshenboim

We construct posterior distributions of the equation of state (EoS) for matter beyond the inner crust of neutron stars by incorporating finite nuclei (FN) constraints within relativistic mean field models. These constraints are implemented…

Nuclear Theory · Physics 2026-01-21 Anagh Venneti , Sarmistha Banik , Bijay K Agrawal

The possible variation of the electromagnetic fine structure constant $\alpha_e$ on cosmological scales arouses great interests in recent years. The strongly lensed gravitational waves and the electromagnetic counterparts could be used to…

General Relativity and Quantum Cosmology · Physics 2018-09-05 Xin Li , Li Tang , Hai-Nan Lin , Li-Li Wang

Sensitivity to temporal variation of the fundamental constants may be strongly enhanced in transitions between narrow close levels of different nature. This enhancement may be realized in a large number of molecules due to cancelation…

Atomic Physics · Physics 2008-11-26 V. V. Flambaum , M. G. Kozlov

Vertex Integrity is a graph measure which sits squarely between two more well-studied notions, namely vertex cover and tree-depth, and that has recently gained attention as a structural graph parameter. In this paper we investigate the…

Computational Complexity · Computer Science 2024-12-04 Michael Lampis , Valia Mitsou

We present a sum-rule extraction of heavy-meson decay constants from the two-point correlator of heavy-light pseudoscalar currents. Our main concern is to control the uncertainties of the decay constants, induced by both input QCD…

High Energy Physics - Phenomenology · Physics 2011-06-15 Wolfgang Lucha , Dmitri Melikhov , Silvano Simula

Recent work has used spectra of about 5000 stars in NGC 6397 that were extracted from a MUSE mosaic to determine the atmospheric parameters for these stars by fitting the spectra against the Goettingen Spectral Library. A significant change…

Solar and Stellar Astrophysics · Physics 2020-04-08 Rashi Jain , Philippe Prugniel , Lucimara Martins , Ariane Lançon

We report unbiased AI measurements of the fine structure constant $\alpha$ in two proximate absorption regions in the spectrum of the quasar HE0515$-$4414. The data are high resolution, high signal to noise, and laser frequency comb…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-18 John K. Webb , Chung-Chi Lee , Dinko Milakovic , Victor V. Flambaum , Vladimir A. Dzuba , Joao Magueijo

The abundance of alpha-process elements such as magnesium and carbon relative to iron measured from the broad emission lines of QSOs can serve as a diagnostic of the star formation and chemical enrichment histories of their host galaxies.…

Astrophysics · Physics 2009-11-10 Michael R. Corbin , Kirk T. Korista , Nalaka Kodituwakku , Wolfram Freduling

In order to investigate the formation of O {\sc i} 7771--5 and [O {\sc i}] 6300/6363 lines, extensive non-LTE calculations for neutral atomic oxygen were carried out for wide ranges of model atmosphere parameters, which are applicable to…

Astrophysics · Physics 2011-05-23 Yoichi Takeda

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

Oscillons are extremely long-lived, spatially-localized field configurations in real-valued scalar field theories that slowly lose energy via radiation of scalar waves. Before their eventual demise, oscillons can pass through (one or more)…

High Energy Physics - Theory · Physics 2020-08-05 Hong-Yi Zhang , Mustafa A. Amin , Edmund J. Copeland , Paul M. Saffin , Kaloian D. Lozanov