The discrete specmm of the hydrogen atom moving acmss a stmng magnetic field (E = 7 x 10"-7 x IO'* G) is studied by expanding wavefunctions over a complete onhogonal basis, whose single term pmvides a correct description of an mmic state at large pseudomomenta K of the h'ansverse motion. Wavefunctions, energies, atomic sires and oscillator strengths of radiative transitions a~ calculated and analysed in a wide range of K values. AU these quantities undergo radical changes when the atom moves acioss the field. The discrete s p e c " remains infinite at arbitrary K. although the mean transverse velocity cannot exceed some maximum value for lhe bound states. Oscillator e n g t h s change by orders of magnitude and some dipole selection rules are violated.

We set new constraints on a seven-dimensional space of cosmological parameters within the class of inflationary adiabatic models. We use the angular power spectrum of the cosmic microwave background measured over a wide range of in the first flight of the MAXIMA balloon-borne experiment (MAXIMA-1) and the low results from COBE/DMR. We find constraints on the total energy density of the universe, Ω = 1.0 +0.15 −0.30 , the physical density of baryons, Ω b h 2 = 0.03 ± 0.01, the physical density of cold dark matter, Ω cdm h 2 = 0.2 +0.2 −0.1 , and the spectral index of primordial scalar fluctuations, n s = 1.08 ± 0.1, all at the 95% confidence level. By combining our results with measurements of high-redshift supernovae we constrain the value of the cosmological constant and the fractional amount of pressureless matter in the universe to 0.45 < Ω Λ < 0.75 and 0.25 < Ω m < 0.50, at the 95% confidence level. Our results are consistent with a flat universe and the shape parameter deduced from large scale structure, and in marginal agreement with the baryon density from big bang nucleosynthesis. Subject headings: cosmic microwave background-cosmology: observations-large-scale structure of universe

We discuss the cosmological implications of the new constraints on the power spectrum of the Cosmic Microwave Background Anisotropy derived from a new high resolution analysis of the MAXIMA-I measurement. The power spectrum indicates excess power at ℓ ∼ 860 over the average level of power at 411 ≤ ℓ ≤ 785. This excess is statistically significant on the ∼ 95% confidence level. Its position coincides with that of the third acoustic peak as predicted by generic inflationary models, selected to fit the first acoustic peak as observed in the data. The height of the excess power agrees with the predictions of a family of inflationary models with cosmological parameters that are fixed to fit the CMB data previously provided by BOOMERANG-LDB and MAXIMA-I experiments.Our results, therefore, lend support for inflationary models and more generally for the dominance of adiabatic coherent perturbations in the structure formation of the Universe. At the same time, they seem to disfavor a large variety of the non-standard (but inflation-based) models that have been proposed to improve the quality of fits to the CMB data and consistency with other cosmological observables.Within standard inflationary models, our results combined with the COBE-DMR data give best fit values and 95% confidence limits for the baryon density, Ω b h 2 ≃ 0.033±0.013, and the total density, Ω = 0.9 +0.18 −0.16 . The primordial spectrum slope (n s ) and the optical depth to the last scattering surface (τ c ) are found to be degenerate and to obey the relation n s ≃ (0.99 ± 0.14) + 0.46τ c , for τ c ≤ 0.5 (all 95% c.l.).