scholarly journals SPACETIME VARIATION OF α AND THE CMB POWER SPECTRA AFTER THE RECOMBINATION

2011 ◽  
Vol 26 (01) ◽  
pp. 43-52 ◽  
Author(s):  
XIULIAN WANG ◽  
MINGZHE LI
Keyword(s):  
Fine Structure ◽  
Scalar Field ◽  
Power Spectra ◽  
Structure Constant ◽  
Fine Structure Constant ◽  
Microwave Background ◽  
Minimal Coupling ◽  
Spatial Fluctuation ◽  
Light Scalar ◽  
Dynamical Nature

The possible variation of the fine structure constant may be due to the non-minimal coupling of the electromagnetic field to a light scalar field which can be the candidate of dark energy. Its dynamical nature renders the fine structure constant varies with time as well as space. In this paper we point out that the spatial fluctuation of the fine structure will modify the power spectra of the temperature and the polarization of the cosmic microwave background. We show explicitly that the fluctuations of the coupled scalar field generate new temperature anisotropies at the linear order and induce a B mode to the polarization at higher order in general.

A FIVE DIMENSIONAL MODEL OF EFFECTIVE GRAVITATIONAL AND FINE-STRUCTURE CONSTANTS

2002 ◽  
Vol 17 (29) ◽  
pp. 4317-4323 ◽  
Author(s):  
J. P. MBELEK ◽  
M. LACHIÈZE-REY
Keyword(s):  
Fine Structure ◽  
Scalar Field ◽  
Gravitational Constant ◽  
Structure Constant ◽  
Fine Structure Constant ◽  
Five Dimensional Model ◽  
Bulk Scalar Field ◽  
Structure Constants ◽  
Good Agreement ◽  
Kaluza Klein

It is shown that the coupling of the Kaluza-Klein (KK) internal scalar field both to an external stabilizing bulk scalar field and to the geomagnetic field may explain the observed dispersion in laboratory measurements of the (effective) gravitational constant. Except the PTB 95 value, the predictions are found in good agreement with all of the experimental data. The cosmological variation of the fine-structure constant is also addressed.

scholarly journals Accelerating universe and the time-dependent fine-structure constant

2009 ◽  
Vol 5 (H15) ◽  
pp. 302-302
Author(s):  
Yasunori Fujii
Keyword(s):  
Fine Structure ◽  
Scalar Field ◽  
Structure Constant ◽  
Theoretical Background ◽  
Point Of View ◽  
Fine Structure Constant ◽  
Time Variability ◽  
Accelerating Universe ◽  
Tensor Theory ◽  
The Right

I start with assuming a gravitational scalar field as the dark-energy supposed to be responsible for the accelerating universe. Also from the point of view of unification, a scalar field implies a time-variability of certain “constants” in Nature. In this context I once derived a relation for the time-variability of the fine-structure constant α: Δα/α =ζ Ƶ(α/π) Δσ, where ζ and Ƶ are the constants of the order one, while σ on the right-hand side is the scalar field in action in the accelerating universe. I use the reduced Planckian units with c=ℏ =MP(=(8π G)−1/2)=1. I then compared the dynamics of the accelerating universe, on one hand, and Δα/α derived from the analyses of QSO absorption lines, Oklo phenomenon, also different atomic clocks in the laboratories, on the other hand. I am here going to discuss the theoretical background of the relation, based on the scalar-tensor theory invented first by Jordan in 1955.

scholarly journals CONSTRAINTS ON THAWING SCALAR FIELD MODELS FROM FUNDAMENTAL CONSTANTS

2013 ◽  
Vol 22 (07) ◽  
pp. 1350035 ◽  
Author(s):  
QING GAO ◽  
YUNGUI GONG
Keyword(s):  
Fine Structure ◽  
Dark Energy ◽  
Scalar Field ◽  
Observational Data ◽  
Dark Energy Model ◽  
Structure Constant ◽  
Energy Model ◽  
Fine Structure Constant ◽  
Density Parameter ◽  
Scalar Field Models

We consider a dark energy model with a relation between the equation of state parameter w and the energy density parameter Ωϕ derived from thawing scalar field models. Assuming the variation of the fine structure constant is caused by dark energy, we use the observational data of the variation of the fine structure constant to constrain the current value of w0 and Ωϕ0 for the dark energy model. At the 1σ level, the observational data excluded some areas around w0 = –1, which explains the positive detection of the variation of the fine structure constant at the 1σ level, but ΛCDM model is consistent with the data at the 2σ level.

Δα/α FROM QSO ABSORPTION LINES DRIVEN BY AN OSCILLATING SCALAR FIELD

2005 ◽  
Vol 14 (03n04) ◽  
pp. 677-685 ◽  
Author(s):  
YASUNORI FUJII ◽  
SHUNTARO MIZUNO
Keyword(s):  
Fine Structure ◽  
Scalar Field ◽  
Structure Constant ◽  
Oscillatory Behavior ◽  
Absorption Lines ◽  
Fine Structure Constant ◽  
Time Variability ◽  
The Past

The new result on the QSO absorption lines from the VLT–UVES sample is compared with the past reports on the time-variability of the fine-structure "constant" derived from the Keck/HIRES observation, on the basis of an oscillatory behavior of the scalar field supposed to be responsible for the cosmological acceleration.

NEW LIMITS ON THE FUNDAMENTAL CONSTANTS FROM THE CMB DATA

2013 ◽  
Vol 23 ◽  
pp. 391-399
Author(s):  
ELOISA MENEGONI ◽  
ALESSANDRO MELCHIORRI ◽  
ERMINIA CALABRESE ◽  
SILVIA GALLI
Keyword(s):  
Fine Structure ◽  
Dark Energy ◽  
Structure Constant ◽  
Theoretical Models ◽  
Big Bang ◽  
Current Data ◽  
Fine Structure Constant ◽  
Microwave Background ◽  
Satellite Mission ◽  
Cosmological Data

The Cosmic Microwave Background anisotropies provide a unique opportunity to constrain simultaneous variations of the fine-structure constant α and Newton's gravitational constant G. Those correlated variations are possible in a wide class of theoretical models. In this brief paper we show that the current data, assuming that particle masses are constant, gives no clear indication for such variations, but already prefers that any relative variations in α should be of the same sign of those of G for variations of ≈ 1%. We also show that a cosmic complementarity is present with Big Bang Nucleosynthesis, and that a combination of current CMB and BBN data strongly constraints simultaneous variations in α and G. We finally discuss the future bounds achievable by the Planck satellite mission. We discuss present and future cosmological constraints on variations of the fine structure constant α induced by an early dark energy component having the simplest allowed (linear) coupling to electromagnetism. We find that current cosmological data show no variation of the fine structure constant at recombination respect to the present-day value, with α/α0 = 0.975 ± 0.020 at 95% c.l., constraining the energy density in early dark energy to Ωe < 0.060 at 95% c.l.

BOUND ON THE TIME VARIATION OF THE FINE STRUCTURE CONSTANT DRIVEN BY QUINTESSENCE

2005 ◽  
Vol 14 (02) ◽  
pp. 335-343 ◽  
Author(s):  
DA-SHIN LEE ◽  
WOLUNG LEE ◽  
KIN-WANG NG
Keyword(s):  
Fine Structure ◽  
Scalar Field ◽  
Time Variation ◽  
Structure Constant ◽  
Fine Structure Constant ◽  
Fifth Force

The bound on the time variation of the fine structure constant (α) driven by the dynamics of quintessence scalar field which is coupled to electromagnetism is discussed using phenomenological quintessential models constrained by SNIa and CMB observations. We find that those models allowing early quintessence give the largest variation Δα at the decoupling epoch. Furthermore, the fifth force experiments imply that Δα/α is less than about 0.1%.

LIMIT ON THE TIME VARIATION OF THE FINE STRUCTURE CONSTANT DRIVEN BY QUINTESSENCE

2004 ◽  
Vol 19 (13n16) ◽  
pp. 1089-1092 ◽  
Author(s):  
WOLUNG LEE ◽  
KIN-WANG NG ◽  
DA-SHIN LEE
Keyword(s):  
Fine Structure ◽  
Dark Energy ◽  
Scalar Field ◽  
Time Variation ◽  
Structure Constant ◽  
Fine Structure Constant ◽  
Fifth Force

We study the time variation of the fine structure constant driven by quintessential dark energy which is coupled to electromagnetism. By employing phenomenological quintessential models which provide the scalar field with maximal dynamics and satisfy the constraints from SNIa observations and the WMAP, we show that the fifth force experiments restrict the variation of the value of α at the decoupling epoch with respect to the present-day value from being less than about 0.1%.

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