scholarly journals Cosmic Tangle: Loop Quantum Cosmology and CMB Anomalies

Universe ◽  
2021 ◽  
Vol 7 (6) ◽  
pp. 186
Author(s):  
Martin Bojowald
Keyword(s):  
Cosmic Microwave Background ◽  
Quantum Cosmology ◽  
Loop Quantum Cosmology ◽  
Microwave Background ◽  
Recent Claim

Loop quantum cosmology is a conflicted field in which exuberant claims of observability coexist with serious objections against the conceptual and physical viability of its current formulations. This contribution presents a non-technical case study of the recent claim that loop quantum cosmology might alleviate anomalies in the observations of the cosmic microwave background.

scholarly journals Hybrid loop quantum cosmology and predictions for the cosmic microwave background

2017 ◽  
Vol 96 (10) ◽  
Author(s):  
Laura Castelló Gomar ◽  
Guillermo A. Mena Marugán ◽  
Daniel Martín de Blas ◽  
Javier Olmedo
Keyword(s):  
Cosmic Microwave Background ◽  
Quantum Cosmology ◽  
Loop Quantum Cosmology ◽  
Microwave Background

scholarly journals Anomalies in the Cosmic Microwave Background and Their Non-Gaussian Origin in Loop Quantum Cosmology

2021 ◽  
Vol 8 ◽  
Author(s):  
Ivan Agullo ◽  
Dimitrios Kranas ◽  
V. Sreenath
Keyword(s):  
Cosmic Microwave Background ◽  
Quantum Cosmology ◽  
Statistical Significance ◽  
New Physics ◽  
Common Origin ◽  
Loop Quantum Cosmology ◽  
Microwave Background ◽  
Λcdm Model ◽  
Non Gaussian ◽  
Dipolar Modulation

Anomalies in the cosmic microwave background (CMB) refer to features that have been observed, mostly at large angular scales, and which show some tension with the statistical predictions of the standard ΛCDM model. In this work, we focus our attention on power suppression, dipolar modulation, a preference for odd parity, and the tension in the lensing parameter AL. Though the statistical significance of each individual anomaly is inconclusive, collectively they are significant, and could indicate new physics beyond the ΛCDM model. In this article, we present a brief, but pedagogical introduction to CMB anomalies and propose a common origin in the context of loop quantum cosmology.

scholarly journals Cosmic Tango Between the Very Small and the Very Large: Addressing CMB Anomalies Through Loop Quantum Cosmology

2021 ◽  
Vol 8 ◽  
Author(s):  
Abhay Ashtekar ◽  
Brajesh Gupt ◽  
V. Sreenath
Keyword(s):  
Power Spectrum ◽  
Quantum Gravity ◽  
Cosmic Microwave Background ◽  
Quantum Cosmology ◽  
Large Scale ◽  
Loop Quantum Gravity ◽  
Statistical Significance ◽  
Loop Quantum Cosmology ◽  
Microwave Background

While the standard, six-parameter, spatially flat ΛCDM model has been highly successful, certain anomalies in the cosmic microwave background bring out a tension between this model and observations. The statistical significance of any one anomaly is small. However, taken together, the presence of two or more of them imply that according to standard inflationary theories we live in quite an exceptional Universe. We revisit the analysis of the PLANCK collaboration using loop quantum cosmology, where an unforeseen interplay between the ultraviolet and the infrared makes the primordial power spectrum scale dependent at very small k. Consequently, we are led to a somewhat different ΛCDM Universe in which anomalies associated with large scale power suppression and the lensing amplitude are both alleviated. The analysis also leads to new predictions for future observations. This article is addressed both to cosmology and loop quantum gravity communities, and we have attempted to make it self-contained.

scholarly journals Tachyon warm inflation with the effects of loop quantum cosmology in the light of Planck 2015

2018 ◽  
Vol 27 (05) ◽  
pp. 1850056 ◽  
Author(s):  
Vahid Kamali ◽  
Spyros Basilakos ◽  
Ahmad Mehrabi ◽  
Meysam Motaharfar ◽  
Erfan Massaeli
Keyword(s):  
Scalar Field ◽  
Quantum Cosmology ◽  
Loop Quantum Cosmology ◽  
Tachyon Field ◽  
Microwave Background ◽  
Planck Data ◽  
Warm Inflation ◽  
Slow Roll ◽  
Background Data ◽  
Cosmic Microwave Background Data

We investigate the observational signatures of quantum cosmology in the Cosmic Microwave Background data provided by Planck collaboration. We apply the warm inflationary paradigm with a tachyon scalar field to the loop quantum cosmology. In this context, we first provide the basic cosmological functions in terms of the tachyon field. We then obtain the slow-roll parameters and the power spectrum of scalar and tensor fluctuations, respectively. Finally, we study the performance of various warm inflationary scenarios against the latest Planck data and we find a family of models which are in agreement with the observations.

scholarly journals Emergence of a classical Universe from quantum gravity and cosmology

2012 ◽  
Vol 370 (1975) ◽  
pp. 4566-4575 ◽  
Author(s):  
Claus Kiefer
Keyword(s):  
Quantum Theory ◽  
Gravitational Field ◽  
Quantum Gravity ◽  
Cosmic Microwave Background ◽  
Quantum Cosmology ◽  
Microwave Background ◽  
Essential Ingredient ◽  
Universal Quantum ◽  
The Universe ◽  
Ordinary Quantum

I describe how we can understand the classical appearance of our world from a universal quantum theory. The essential ingredient is the process of decoherence. I start with a general discussion in ordinary quantum theory and then turn to quantum gravity and quantum cosmology. There is a whole hierarchy of classicality from the global gravitational field to the fluctuations in the cosmic microwave background, which serve as the seeds for the structure in the Universe.

Small‐Scale Cosmic Microwave Background Observations at 8.4 GHz

1997 ◽  
Vol 483 (1) ◽  
pp. 38-50 ◽  
Author(s):  
R. Bruce Partridge ◽  
Eric A. Richards ◽  
Edward B. Fomalont ◽  
K. I. Kellerman ◽  
Rogier A. Windhorst
Keyword(s):  
Cosmic Microwave Background ◽  
Small Scale ◽  
Microwave Background

scholarly journals The evolution of the cosmic microwave background temperature

2011 ◽  
Vol 526 ◽  
pp. L7 ◽  
Author(s):  
P. Noterdaeme ◽  
P. Petitjean ◽  
R. Srianand ◽  
C. Ledoux ◽  
S. López
Keyword(s):  
Cosmic Microwave Background ◽  
Microwave Background ◽  
Cosmic Microwave Background Temperature ◽  
Background Temperature
Sign in / Sign up

Export Citation Format

Share Document