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.

Recent results from BOOMERANG-98 and MAXIMA-1, taken together with COBE DMR, provide consistent and high signal-to-noise measurements of the cosmic microwave background power spectrum at spherical harmonic multipole bands over 2

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