scholarly journals Cosmological perturbations of quantum-mechanical origin and anisotropy of the microwave background

1993 ◽  
Vol 70 (16) ◽  
pp. 2371-2374 ◽  
Author(s):  
L. P. Grishchuk
Keyword(s):  
Quantum Mechanical ◽  
Cosmological Perturbations ◽  
Microwave Background

scholarly journals ON SIGNATURES OF SHORT DISTANCE PHYSICS IN THE COSMIC MICROWAVE BACKGROUND

2002 ◽  
Vol 17 (25) ◽  
pp. 3663-3680 ◽  
Author(s):  
ROBERT H. BRANDENBERGER ◽  
JÉRÔME MARTIN
Keyword(s):  
Excited State ◽  
Cosmic Microwave Background ◽  
Short Distance ◽  
The State ◽  
Inflationary Universe ◽  
Late Time ◽  
Cosmological Perturbations ◽  
Microwave Background ◽  
Hubble Radius

Following a self-contained review of the basics of the theory of cosmological perturbations, we discuss why the conclusions reached in the recent paper by Kaloper et al.1 are too pessimistic estimates of the amplitude of possible imprints of trans-Planckian (string) physics on the spectrum of cosmic microwave anisotropies in an inflationary universe. It is shown that the likely origin of large trans-Planckian effects on late time cosmological fluctuations comes from nonadiabatic evolution of the state of fluctuations while the wavelength is smaller than the Planck (string) scale, resulting in an excited state at the time that the wavelength crosses the Hubble radius during inflation.

scholarly journals A SEMI-ANALYTICAL APPROACH TO PERTURBATIONS IN MUTATED HILLTOP INFLATION

2012 ◽  
Vol 21 (02) ◽  
pp. 1250017 ◽  
Author(s):  
BARUN KUMAR PAL ◽  
SUPRATIK PAL ◽  
B. BASU
Keyword(s):  
Power Spectrum ◽  
Cosmic Microwave Background ◽  
Numerical Computation ◽  
Analytical Approach ◽  
Cosmological Perturbations ◽  
Microwave Background ◽  
Analytical Treatment ◽  
Angular Power Spectrum

We study cosmological perturbations and observational aspects for mutated hilltop model of inflation. Employing mostly analytical treatment, we evaluate observable parameters during inflation as well as post-inflationary perturbations. This further leads to exploring observational aspects related to cosmic microwave background (CMB) radiation. This semi-analytical treatment reduces complications related to numerical computation to some extent for studying the different phenomena related to CMB angular power spectrum for mutated hilltop inflation.

Search for primordial symmetry breakings in CMB

2016 ◽  
Vol 31 (21) ◽  
pp. 1640003 ◽  
Author(s):  
Maresuke Shiraishi
Keyword(s):  
Symmetry Breaking ◽  
Cosmic Microwave Background ◽  
Observational Data ◽  
Theoretical Models ◽  
Space Representation ◽  
Harmonic Space ◽  
Late Time ◽  
Cosmological Perturbations ◽  
Microwave Background ◽  
Symmetry Breakings

There are possibilities to violate symmetries (e.g. parity and rotational invariance) in the primordial cosmological fluctuations. Such symmetry breakings can imprint very rich signatures in late-time phenomena, which may be possible to observe. Especially, Cosmic Microwave Background (CMB) will change its face drastically, corresponding to the symmetry-breaking types, since the harmonic-space representation is very sensitive to the statistical, spin and angular dependences of cosmological perturbations. Here, we discuss (1) general responses of CMB to the symmetry breakings, (2) some theoretical models creating interesting CMB signatures, and (3) aspects of the estimation from observational data.

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