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 Time-Varying Fine-Structure Constant Requires Cosmological Constant

2019 ◽  
Author(s):  
Rainer Kühne
Keyword(s):  
Fine Structure ◽  
Cosmological Constant ◽  
Structure Constant ◽  
Preliminary Evidence ◽  
Fine Structure Constant ◽  
Time Varying ◽  
De Sitter ◽  
Sitter Universe ◽  
De Sitter Universe

Webb et al. presented preliminary evidence for a time-varying fine-structure constant. We show Teller's formula for this variation to be ruled out within the Einstein-de Sitter universe, however, it is compatible with cosmologies which require a large cosmological constant.

scholarly journals Time-varying fine structure constant from naturally ultralight dark matter

2021 ◽  
Vol 104 (7) ◽  
Author(s):  
Dawid Brzeminski ◽  
Zackaria Chacko ◽  
Abhish Dev ◽  
Anson Hook
Keyword(s):  
Dark Matter ◽  
Fine Structure ◽  
Structure Constant ◽  
Fine Structure Constant ◽  
Time Varying

scholarly journals TIME-VARYING FINE-STRUCTURE CONSTANT REQUIRES COSMOLOGICAL CONSTANT

1999 ◽  
Vol 14 (27) ◽  
pp. 1917-1922 ◽  
Author(s):  
RAINER W. KÜHNE
Keyword(s):  
Fine Structure ◽  
Cosmological Constant ◽  
Structure Constant ◽  
Preliminary Evidence ◽  
Fine Structure Constant ◽  
Time Varying ◽  
De Sitter ◽  
Sitter Universe ◽  
De Sitter Universe

Webb et al. presented preliminary evidence for a time-varying fine-structure constant. We show Teller's formula for this variation to be ruled out within the Einstein–de Sitter universe, however, it is compatible with cosmologies which require a large cosmological constant.

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
Sign in / Sign up

Export Citation Format

Share Document