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Supernova evidence for a negative-pressure dark energy (e.g., cosmological constant or quintessence) that contributes a fraction $\Omega_\Lambda\simeq0.7$ of closure density has been bolstered by the discrepancy between the total density,…

Astrophysics · Physics 2007-05-23 Marc Kamionkowski , Ari Buchalter

CMB angular spectrum measurements suggest a flat universe. This paper clarifies the relation between geometry and the spherical harmonic index of the first acoustic peak ($\ell_{peak}$). Numerical and analytic calculations show that…

Astrophysics · Physics 2007-05-23 T. A. Marriage

Analytic formulas for the position of the first acoustic peak in the CMB are derived and discussed. They are generalized to the case of a time-dependent dark energy component and it is shown how the cosmic parameters $\Omega_M$ and…

Astrophysics · Physics 2007-05-23 Paul H. Frampton

This talk describes an analytic calculation of the position of the first accoustic peak as a function of the matter density and the cosmological constant (work with Y.J. Ng and R. Rohm), agreeing with independent numerical studies. There is…

Astrophysics · Physics 2009-10-31 P. H. Frampton

Recent results from BOOMERANG-98 and MAXIMA-1, taken together with COBE-DMR, provide consistent and high signal-to-noise measurements of the CMB power spectrum at spherical harmonic multipole bands over $2<\ell\lta800$. Analysis of the…

The locations and amplitudes of three acoustic peaks and two dips in the last releases of the Boomerang, MAXIMA and DASI measurements of the cosmic microwave background (CMB) anisotropy power spectra as well as their statistical confidence…

Astrophysics · Physics 2009-11-07 R. Durrer , B. Novosyadlyj , S. Apunevych

We report the first results from the BOOMERanG experiment, which mapped at 90, 150, 240 and 410 GHz a wide (3%) region of the microwave sky with minimal local contamination. From the data of the best 150 GHz detector we find evidence for a…

We discuss constraints on so-called `varying speed of light theories' coming from the physics of the early universe. Specifically, we consider the position of the first acoustic peak of the CMB angular power spectrum, showing that the…

Astrophysics · Physics 2009-10-31 P. P. Avelino , C. J. A. P. Martins , G. Rocha

The acoustic peak in the CMB power spectrum is sensitive to causal processes and cosmological parameters in the early universe up to the time of last scattering. We provide limits on correlated spatial variations of the peak height and peak…

Astrophysics · Physics 2009-11-10 Evan P. Donoghue , John F. Donoghue

Within the $\Lambda$CDM cosmological model, the absolute value of Einstein's cosmological constant $\Lambda$, sometimes expressed as the gravitating mass-energy density $\rho_\Lambda$ of the physical vacuum, is a fundamental constant of…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-22 J. Prat , C. Hogan , C. Chang , J. Frieman

The locations of the peaks of the CMB spectrum are sensitive indicators of cosmological parameters, yet there is no known analytic formula which accurately describes their dependence on them. We parametrize the location of the peaks as l_m…

Astrophysics · Physics 2008-11-26 Michael Doran , Matthew Lilley

Recent measurements of the cosmic microwave background radiation by the Boomerang experiment indicate that the universe is spatially flat. Here some simple back-of-the-envelope calculations are used to explain their result. The main result…

Astrophysics · Physics 2009-10-31 Neil J. Cornish

Cosmological theories for the origin and evolution of structure in the Universe are highly predictive of the form of the angular power spectrum of cosmic microwave background fluctuations. We present new results from a comprehensive study…

Astrophysics · Physics 2007-05-23 Stephen Hancock , Graca Rocha

The widely cited formula $\ell_1\simeq 200 \Omega_0^{-1/2}$ for the multipole number of the first Doppler peak is not even a crude approximation in the case of greatest current interest, in which the cosmic mass density is less than the…

Astrophysics · Physics 2008-11-26 Steven Weinberg

We show that recent measurements of the power spectrum of cosmic microwave background anisotropies by BOOMERanG and MAXIMA can be characterized by four observables, the position of the first acoustic peak l_1= 206 pm 6, the height of the…

Astrophysics · Physics 2009-10-07 Wayne Hu , Masataka Fukugita , Matias Zaldarriaga , Max Tegmark

Despite the great progress of current cosmological measurements, the nature of the dominant component of the universe, coined dark energy, is still an open question. Early Dark Energy is a possible candidate which may also alleviate some…

Cosmology and Nongalactic Astrophysics · Physics 2015-01-07 Maria Archidiacono , Laura Lopez-Honorez , Olga Mena

A key prediction of cosmological theories for the origin and evolution of structure in the Universe is the existence of a `Doppler peak' in the angular power spectrum of cosmic microwave background (CMB) fluctuations. We present new results…

Astrophysics · Physics 2020-11-25 S. Hancock , G. Rocha , A. N. Lasenby , C. M. Gutierrez

We show how estimates of parameters characterizing inflation-based theories of structure formation localized over the past year when large scale structure (LSS) information from galaxy and cluster surveys was combined with the rapidly…

The pattern of acoustic peaks in the sub-horizon power spectrum of primordial density anisotropies at recombination can be naturally understood in the framework of standard Friedmann-Robertson-Walker cosmology (without inflation) as a…

General Relativity and Quantum Cosmology · Physics 2007-05-23 David H. Oaknin

Variations in $\Omega$, the total density of the Universe, leave a clear and distinctive imprint on the power spectrum of temperature fluctuations in the cosmic microwave background (CMB). This signature is virtually independent of other…

Astrophysics · Physics 2009-10-28 Gerard Jungman , Marc Kamionkowski , Arthur Kosowsky , David N. Spergel
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