Mário G. Santos

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Adams et al. (1997b) have noted that according to our current understanding of the unification of fundamental interactions, there should have been phase transitions associated with spontaneous symmetry breaking during the inflationary era. This may have resulted in the breaking of scale-invariance of the primordial density perturbation for brief periods. A(More)
We present forecasts for constraints on cosmological models which can be obtained by forthcoming radio continuum surveys: the wide surveys with the LOw Frequency ARray (LOFAR), Australian Square Kilometre Array Pathfinder (ASKAP) and the Westerbork Observations of the Deep APERTIF Northern sky (WODAN). We use simulated catalogues appropriate to the planned(More)
We study contributions from inhomogeneous (patchy) reionization to arcminute scale (1000 < ℓ < 10, 000) cosmic microwave background (CMB) anisotropies. We show that inhomo-geneities in the ionization fraction, rather than in the mean density, dominate both the temperature and the polarization power spectra. Depending on the ionization history and the(More)
We consider decay chains of the type P → M + · · · → f + · · ·, where M is a neutral meson that may mix with its antiparticle M , before decaying into the final state f. P may be either a heavier neutral meson or a charged meson. We perform a rephasing-invariant analysis of the quantities that show up in such cascade decays. If the decay P → M + · · · (or(More)
In the light of the recent Boomerang and Maxima observations of the CMB which show an anomalously low second acoustic peak, we reexamine the prediction by Adams et al (1997) that this would be the consequence of a 'step' in the primordial spectrum induced by a spontaneous symmetry breaking phase transition during primordial inflation. We demonstrate that a(More)
In this paper we explore the impact of including redshift information on cosmological applications with the forthcoming generation of large-scale, deep radio continuum surveys. By cross-matching these radio surveys with shallow optical to near-infrared surveys we can essentially separate the source distribution into a low redshift sample and the high-z tail(More)
We propose observations of the molecular gas distribution during the era of reionization. At z ∼ 6 to 8, 12 CO(J = 1 − 0) line intensity results in a mean brightness temperature of about 0.5 µK with rms fluctuations of 0.1 µK at 1 to 10 Mpc spatial scales, corresponding to 30 arcminute angular scales. This intensity fluctuations can be mapped with an(More)
We describe different methods for estimating the bispectrum of Cosmic Microwave Background data. In particular we construct a minimum variance estimator for the flat-sky limit and compare results with previously-studied frequentist methods. Application to the MAXIMA dataset shows consistency with primordial Gaussianity. Weak quadratic non-Gaussianity is(More)
We calculate the absolute intensity and anisotropies of the Lyman-α radiation field present during the epoch of reionization. We consider emission from both galaxies and the intergalactic medium (IGM) and take into account the main contributions to the production of Lyman-α photons: recombi-nations, collisions, continuum emission from galaxies and(More)
The large-scale structure of the Universe supplies crucial information about the physical processes at play at early times. Unresolved maps of the intensity of 21 cm emission from neutral hydrogen HI at redshifts z=/~1-5 are the best hope of accessing the ultralarge-scale information, directly related to the early Universe. A purpose-built HI intensity(More)