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We have made a likelihood statistical analysis of the angular correlations in the {\it COBE}-DMR two-year sky maps by Monte Carlo simulation of the temperature fluctuations. We assume an open universe and consider as primordial power…

Astrophysics · Physics 2015-06-24 L. Cayon , E. Martinez-Gonzalez , J. L. Sanz , N. Sugiyama , S. Torres

The current experimentally measured parameters of the Standard Model (SM) suggest that our Universe lies in a metastable electroweak vacuum, where the Higgs field is prone to vacuum decay to a lower state with catastrophic consequences. Our…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-13 Andreas Mantziris

In this work, we examine cosmological constraints on models of composite inflation based on the slow-roll approximation by using the recent Planck measurement. We compare the spectral index of curvature perturbation (and its running) and…

High Energy Physics - Phenomenology · Physics 2016-06-30 Phongpichit Channuie

Is there new physics hidden in the four-point function of the cosmic microwave background (CMB)? We conduct a detailed analysis of the Planck PR4 temperature and polarization trispectrum for $\ell\in[2,2048]$. Using the theoretical and…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-30 Oliver H. E. Philcox

A Planck scale inflationary era -- in a quantum gravity theory predicting discreteness of quantum geometry at the fundamental scale -- produces the scale invariant spectrum of inhomogeneities with very small tensor-to-scalar ratio of…

General Relativity and Quantum Cosmology · Physics 2025-04-30 Gabriel R. Bengochea , Gabriel Leon , Alejandro Perez

We describe the implications of cosmic microwave background (CMB) observations and galaxy and cluster surveys of large scale structure (LSS) for theories of cosmic structure formation, especially emphasizing the recent Boomerang and Maxima…

The cosmic spatial curvature parameter $\Omega_k$ is constrained, primarily by cosmic microwave background (CMB) data, to be very small. Observations of the cosmic distance ladder and the large scale structure can provide independent checks…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-05 Haoting Xu , Zhiqi Huang , Zhenjie Liu , Haitao Miao

For variable gravity models the strength of gravity, as measured by Newton's ``constant'' or the Planck mass, depends on the value of a scalar field, the cosmon. We discuss two simple four-parameter models with a quadratic or constant…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-15 C. Wetterich

We impose constraints on the topology of the Universe determined from a search for matched circles in the cosmic microwave background (CMB) temperature anisotropy patterns of the 7-year WMAP data. We pay special attention to the sensitivity…

Cosmology and Nongalactic Astrophysics · Physics 2013-03-19 P. Bielewicz , A. J. Banday , K. M. Gorski

We present measurements of the cosmic microwave background (CMB) lensing potential using the final $\textit{Planck}$ 2018 temperature and polarization data. We increase the significance of the detection of lensing in the polarization maps…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-16 Planck Collaboration , N. Aghanim , Y. Akrami , M. Ashdown , J. Aumont , C. Baccigalupi , M. Ballardini , A. J. Banday , R. B. Barreiro , N. Bartolo , S. Basak , K. Benabed , J. -P. Bernard , M. Bersanelli , P. Bielewicz , J. J. Bock , J. R. Bond , J. Borrill , F. R. Bouchet , F. Boulanger , M. Bucher , C. Burigana , E. Calabrese , J. -F. Cardoso , J. Carron , A. Challinor , H. C. Chiang , L. P. L. Colombo , C. Combet , B. P. Crill , F. Cuttaia , P. de Bernardis , G. de Zotti , J. Delabrouille , E. Di Valentino , J. M. Diego , O. Doré , M. Douspis , A. Ducout , X. Dupac , G. Efstathiou , F. Elsner , T. A. Enßlin , H. K. Eriksen , Y. Fantaye , R. Fernandez-Cobos , F. Forastieri , M. Frailis , A. A. Fraisse , E. Franceschi , A. Frolov , S. Galeotta , S. Galli , K. Ganga , R. T. Génova-Santos , M. Gerbino , T. Ghosh , J. González-Nuevo , K. M. Górski , S. Gratton , A. Gruppuso , J. E. Gudmundsson , J. Hamann , W. Handley , F. K. Hansen , D. Herranz , E. Hivon , Z. Huang , A. H. Jaffe , W. C. Jones , A. Karakci , E. Keihänen , R. Keskitalo , K. Kiiveri , J. Kim , L. Knox , N. Krachmalnicoff , M. Kunz , H. Kurki-Suonio , G. Lagache , J. -M. Lamarre , A. Lasenby , M. Lattanzi , C. R. Lawrence , M. Le Jeune , F. Levrier , A. Lewis , M. Liguori , P. B. Lilje , V. Lindholm , M. López-Caniego , P. M. Lubin , Y. -Z. Ma , J. F. Macías-Pérez , G. Maggio , D. Maino , N. Mandolesi , A. Mangilli , A. Marcos-Caballero , M. Maris , P. G. Martin , E. Martínez-González , S. Matarrese , N. Mauri , J. D. McEwen , A. Melchiorri , A. Mennella , M. Migliaccio , M. -A. Miville-Deschênes , D. Molinari , A. Moneti , L. Montier , G. Morgante , A. Moss , P. Natoli , L. Pagano , D. Paoletti , B. Partridge , G. Patanchon , F. Perrotta , V. Pettorino , F. Piacentini , L. Polastri , G. Polenta , J. -L. Puget , J. P. Rachen , M. Reinecke , M. Remazeilles , A. Renzi , G. Rocha , C. Rosset , G. Roudier , J. A. Rubiño-Martín , B. Ruiz-Granados , L. Salvati , M. Sandri , M. Savelainen , D. Scott , C. Sirignano , R. Sunyaev , A. -S. Suur-Uski , J. A. Tauber , D. Tavagnacco , M. Tenti , L. Toffolatti , M. Tomasi , T. Trombetti , J. Valiviita , B. Van Tent , P. Vielva , F. Villa , N. Vittorio , B. D. Wandelt , I. K. Wehus , M. White , S. D. M. White , A. Zacchei , A. Zonca

We investigate the inflationary universe in a theory where two scalar fields non-minimally coupling to the scalar curvature and an extra $R^2$ term exist and the conformal invariance is broken. In particular, the slow-roll inflation is…

High Energy Physics - Theory · Physics 2016-03-01 Kazuharu Bamba

Flat cosmological models with a cosmological constant on the order of the Einstein-de Sitter critical density are enigmatic in the sense that there does not appear to be any natural explanation for why there should be a cosmological…

Astrophysics · Physics 2007-05-23 George Chapline

Determining the spatial curvature $\Omega_K$ of the Universe has long been crucial in cosmology. In practice, this effort is often entangled with assumptions of dark energy. A combination of distance ($D_{\rm M}$, $D_{\rm L}$) and expansion…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-30 Zhennan Li , Pengjie Zhang

Experimental evidence over a number of recent years has shown the density parameter of the universe omega converging to the critical value of 1, which defines a flat, Euclidean universe. No such calculations have defined a critical value…

General Physics · Physics 2013-06-20 Peter Rowlands

Though predictions of the simplest inflationary cosmological models with cold dark matter, flat space and approximately flat initial spectrum of adiabatic perturbations are remarkably close to observational data, we have to go beyond them…

Astrophysics · Physics 2011-04-15 A. A. Starobinsky

In this paper, we combine the latest observational data, including the WMAP five-year data (WMAP5), BOOMERanG, CBI, VSA, ACBAR, as well as the Baryon Acoustic Oscillations (BAO) and Type Ia Supernoave (SN) "Union" compilation (307 sample)…

Astrophysics · Physics 2008-11-26 Jun-Qing Xia , Hong Li , Gong-Bo Zhao , Xinmin Zhang

We argue that the observed large-scale cosmic microwave anomalies, discovered by WMAP and confirmed by the Planck satellite, are most naturally explained in the context of a marginally-open universe. Particular focus is placed on the dipole…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-05 Andrew R Liddle , Marina Cortês

The value of the tensor-to-scalar ratio $r$ in the region allowed by the latest $Planck$ 2015 measurements can be associated to a large variety of inflationary models. We discuss here the potential of future Cosmic Microwave Background…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-17 Miguel Escudero , Héctor Ramírez , Lotfi Boubekeur , Elena Giusarma , Olga Mena

Several Cardassian universe models including the original, modified polytropic and exponential Cardassian models are constrained by the latest Constitution Type Ia supernova data, the position of the first acoustic peak of CMB from the five…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Chao-Jun Feng , Xin-Zhou Li