Fine-structure constant and entropy in the early universe

1975 ◽  
Vol 11 (4) ◽  
pp. 722-723 ◽  
Author(s):  
Moorad Alexanian
Keyword(s):  
Fine Structure ◽  
Early Universe ◽  
Structure Constant ◽  
Fine Structure Constant

scholarly journals Early-universe constraints on a time-varying fine structure constant

2001 ◽  
Vol 64 (10) ◽  
Author(s):  
P. P. Avelino ◽  
S. Esposito ◽  
G. Mangano ◽  
C. J. A. P. Martins ◽  
A. Melchiorri ◽  
...  
Keyword(s):  
Fine Structure ◽  
Early Universe ◽  
Structure Constant ◽  
Fine Structure Constant ◽  
Time Varying

scholarly journals Variation of the fundamental constants over the cosmological time: veracity of Dirac’s intriguing hypothesis

2016 ◽  
Vol 94 (1) ◽  
pp. 89-94 ◽  
Author(s):  
Cláudio Nassif ◽  
A.C. Amaro de Faria
Keyword(s):  
Fine Structure ◽  
Early Universe ◽  
Early Period ◽  
Planck Scale ◽  
Structure Constant ◽  
Energy Scale ◽  
Fine Structure Constant ◽  
Cosmological Time ◽  
Age Of The Universe ◽  
The Universe

We investigate how the universal constants, including the fine structure constant, have varied since the early universe close to the Planck energy scale (EP ∼ 1019 GeV) and, thus, how they have evolved over the cosmological time related to the temperature of the expanding universe. According to a previous paper (Nassif and Amaro de Faria, Jr. Phys. Rev. D, 86, 027703 (2012). doi:10.1103/PhysRevD.86.027703), we have shown that the speed of light was much higher close to the Planck scale. In the present work, we will go further, first by showing that both the Planck constant and the electron charge were also too large in the early universe. However, we conclude that the fine structure constant (α ≅ 1/137) has remained invariant with the age and temperature of the universe, which is in agreement with laboratory tests and some observational data. Furthermore, we will obtain the divergence of the electron (or proton) mass and also the gravitational constant (G) at the Planck scale. Thus, we will be able to verify the veracity of Dirac’s belief about the existence of “coincidences” between dimensionless ratios of subatomic and cosmological quantities, leading to a variation of G with time, that is, the ratio of the electrostatic to gravitational forces between an electron and a proton (∼1041) is roughly equal to the age of the universe divided by an elementary time constant, so that the strength of gravity, as determined by G, must vary inversely with time in the approximation of lower temperature or for times very far from the early period, to compensate for the time-variation of the Hubble parameter (H ∼ t−1). In short, we will show the validity of Dirac’s hypothesis only for times very far from the early period or T ≪ TP (∼1032 K).

scholarly journals Invariance of the fine structure constant with temperature of the expanding universe

2015 ◽  
Vol 93 (12) ◽  
pp. 1551-1554
Author(s):  
Cláudio Nassif ◽  
A.C. Amaro de Faria
Keyword(s):  
Fine Structure ◽  
Early Universe ◽  
Structure Constant ◽  
Energy Scale ◽  
Fine Structure Constant ◽  
Expanding Universe ◽  
Cosmological Time ◽  
Doubly Special Relativity ◽  
Background Temperature ◽  
Planck Energy

Our goal is to interpret the energy equation from doubly special relativity of Magueijo–Smolin with an invariant Planck energy scale to obtain the speed of light with an explicit dependence on the background temperature of the expanding universe (Nassif and de Faria. Phys. Rev. D, 86, 027703 (2012). doi:10.1103/PhysRevD.86.027703 ). We also investigate how other universal constants, including the fine structure constant, have varied since the early universe and, thus, how they have evolved over the cosmological time related to the temperature of the expanding universe. For instance, we show that both the Planck constant and the electron charge were also too large in the early universe. However, we finally conclude that the fine structure constant has remained invariant with the age and temperature of the universe, which is in agreement with laboratory tests and some observational data.

scholarly journals Time variation of the fine structure constant in the early universe and the Bekenstein model

2007 ◽  
Vol 478 (3) ◽  
pp. 675-684 ◽  
Author(s):  
M. E. Mosquera ◽  
C. G. Scóccola ◽  
S. J. Landau ◽  
H. Vucetich
Keyword(s):  
Fine Structure ◽  
Early Universe ◽  
Time Variation ◽  
Structure Constant ◽  
Fine Structure Constant

scholarly journals New Limit on Space-Time Variations in the Proton-to-Electron Mass Ratio from Analysis of Quasar J110325-264515 Spectra

Symmetry ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 344
Author(s):  
T. D. Le
Keyword(s):  
Fine Structure ◽  
Structure Constant ◽  
Space Time ◽  
Fine Structure Constant ◽  
Electron Mass ◽  
Mass Ratio ◽  
Quasar Spectra ◽  
Time Variations ◽  
Using Data ◽  
The Universe

Astrophysical tests of current values for dimensionless constants known on Earth, such as the fine-structure constant, α , and proton-to-electron mass ratio, μ = m p / m e , are communicated using data from high-resolution quasar spectra in different regions or epochs of the universe. The symmetry wavelengths of [Fe II] lines from redshifted quasar spectra of J110325-264515 and their corresponding values in the laboratory were combined to find a new limit on space-time variations in the proton-to-electron mass ratio, ∆ μ / μ = ( 0.096 ± 0.182 ) × 10 − 7 . The results show how the indicated astrophysical observations can further improve the accuracy and space-time variations of physics constants.

scholarly journals Measurement of the running of the fine structure constant below 1 GeV with the KLOE detector

2019 ◽  
Vol 218 ◽  
pp. 02012
Author(s):  
Graziano Venanzoni
Keyword(s):  
Fine Structure ◽  
Energy Region ◽  
Direct Evidence ◽  
Branching Ratio ◽  
Structure Constant ◽  
Fine Structure Constant ◽  
Recent Measurement ◽  
Single Measurement ◽  
Lepton Universality ◽  
Hadronic Contribution

I will report on the recent measurement of the fine structure constant below 1 GeV with the KLOE detector. It represents the first measurement of the running of α(s) in this energy region. Our results show a more than 5σ significance of the hadronic contribution to the running of α(s), which is the strongest direct evidence both in time-and space-like regions achieved in a single measurement. From a fit of the real part of Δα(s) and assuming the lepton universality the branching ratio BR(ω → µ+µ−) = (6.6 ± 1.4stat ± 1.7syst) · 10−5 has been determined

scholarly journals Fine structure constant and the CMB damping scale

2012 ◽  
Vol 85 (10) ◽  
Author(s):  
Eloisa Menegoni ◽  
Maria Archidiacono ◽  
Erminia Calabrese ◽  
Silvia Galli ◽  
C. J. A. P. Martins ◽  
...  
Keyword(s):  
Fine Structure ◽  
Structure Constant ◽  
Fine Structure Constant
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