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Related papers: Constraining regularization ambiguities in Loop Qu…

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We explore the linearly quantised primordial power spectra associated with palindromic universes. Extending the results of Lasenby et al. [1] and Bartlett et al. [2], we improve the modelling of recombination and include higher orders in…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-13 Metha Prathaban , Will Handley

We perform a cosmological analysis in which we allow the primordial power spectrum of scalar perturbations to assume a shape that is different with respect to the usual power-law, arising from the simplest models of cosmological inflation.…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-22 Stefano Gariazzo

We investigate the question of how tightly we can constrain the cosmological parameters by using the ``cosmic inversion'' method in which we directly reconstruct the power spectrum of primordial curvature perturbations, $P(k)$, from the…

Astrophysics · Physics 2009-10-09 Noriyuki Kogo , Misao Sasaki , Jun'ichi Yokoyama

The comprehensive formulation for loop quantum cosmology in the spatially flat, isotropic model was recently constructed. In this paper, the methods are extended to the anisotropic Bianchi I cosmology. Both the precursor and the improved…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Dah-Wei Chiou

Observations of the Cosmic Microwave Background (CMB) have cemented the notion that the large-scale Universe is both statistically homogeneous and isotropic. But is it invariant also under reflections? To probe this we require…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-25 Oliver H. E. Philcox

We study the projected clustering of photometric luminous red galaxies from the DESI Legacy Survey, combining their angular power spectrum, bispectrum, and cross-correlation with maps of the CMB lensing convergence from the Planck…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-21 Francesco Verdiani , Lea Harscouet , Matteo Zennaro , David Alonso , Boryana Hadzhiyska

Recent Planck data show the anomalies of CMB fluctuations on large angular scales, which confirms the early observations by WMAP. We continue studying an inflationary model, in which before the slow roll inflation the universe is in a…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-15 Zhi-Guo Liu , Zong-Kuan Guo , Yun-Song Piao

Over the last decade, measurements of the CMB anisotropy has spearheaded the remarkable transition of cosmology into a precision science. However, addressing the systematic effects in the increasingly sensitive, high resolution, `full' sky…

Astrophysics · Physics 2009-03-31 Sanjit Mitra , Anand S. Sengupta , Subharthi Ray , Rajib Saha , Tarun Souradeep

We constrain plausible dark energy models, parametrized by multiple candidate equation of state, using the recently published Cosmic Microwave Background (CMB) temperature anisotropy data from Planck together with the WMAP-9 low-$\ell$…

Cosmology and Nongalactic Astrophysics · Physics 2015-04-22 Dhiraj Kumar Hazra , Subhabrata Majumdar , Supratik Pal , Sudhakar Panda , Anjan A. Sen

Upcoming measurements of the small-scale primary cosmic microwave background (CMB) temperature and polarization power spectra ($TT$/$TE$/$EE$) are anticipated to yield transformative constraints on new physics, including the effective…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-26 Fiona McCarthy , J. Colin Hill , Mathew S. Madhavacheril

We extend the phenomenology of loop quantum cosmology (LQC) to second order in perturbations. Our motivation is twofold. On the one hand, since LQC predicts a cosmic bounce that takes place at the Planck scale, the second order…

General Relativity and Quantum Cosmology · Physics 2018-04-04 Ivan Agullo , Boris Bolliet , V. Sreenath

We investigate the consequences of the hybrid quantization approach for primordial perturbations in loop quantum cosmology, obtaining predictions for the cosmic microwave background and comparing them with data collected by the Planck…

General Relativity and Quantum Cosmology · Physics 2017-11-29 Laura Castelló Gomar , Daniel Martín de Blas , Guillermo A. Mena Marugán , Javier Olmedo

We present two novel methods for the estimation of the angular power spectrum of cosmic microwave background (CMB) anisotropies. We assume an absolute CMB experiment with arbitrary asymmetric beams and arbitrary sky coverage. The methods…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-25 Elina Keihänen , Kimmo Kiiveri , Hannu Kurki-Suonio , Martin Reinecke

This paper aims to perform a phenomenological parametrisation of the standard cosmological model, $\Lambda$CDM, to weigh the different physical processes that define the pattern of the angular power spectra of the Cosmic Microwave…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-22 M. Ruiz-Granda , P. Vielva

We forecast the constraints on both Hu-Sawicki model and Bertschinger-Zukin model of modified gravity within the Parameterized Post-Friedmann (PPF) formalism for the Planck satellite experiment by performing the joint analysis of…

Cosmology and Nongalactic Astrophysics · Physics 2013-08-09 Bin Hu , Michele Liguori , Nicola Bartolo , Sabino Matarrese

The Cosmological Principle assumes a statistically isotropic Universe, but the Cosmic Microwave Background (CMB) exhibits some anomalous statistical features, such as the hemispherical power asymmetry, that challenge this core assumption.…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-25 Javier Carrón Duque , Mikel Martin Barandiaran , Joseba Martínez-Arrizabalaga

The WMAP team has recently highlighted the usefulness of combining the Ly-alpha forest constraints with those from the cosmic microwave background (CMB). This combination is particularly powerful as a probe of the primordial shape of the…

Astrophysics · Physics 2009-11-07 Uros Seljak , Patrick McDonald , Alexey Makarov

The Planck mission, designed for making measurements of the cosmic microwave background (CMB) radiation with unprecedented accuracy and angular resolution, is expected to release its first data set in the near future. For the first time in…

Cosmology and Nongalactic Astrophysics · Physics 2015-01-27 Amir Aghamousa , Mihir Arjunwadkar , Tarun Souradeep

We develop a formalism for calculating cosmic microwave background (CMB) temperature and polarization anisotropies in cosmological models with Brans-Dicke gravity. We then modify publicly available Boltzmann codes to calculate numerically…

Astrophysics · Physics 2008-11-26 Xuelei Chen , Marc Kamionkowski

We test a class of holographic models for the very early universe against cosmological observations and find that they are competitive to the standard $\Lambda$CDM model of cosmology. These models are based on three dimensional perturbative…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-01 Niayesh Afshordi , Claudio Coriano , Luigi Delle Rose , Elizabeth Gould , Kostas Skenderis