2,998,020 research outputs found
Comments to On the Accuracy of Lamb Shift Measurements in Hydrogen (Physica Scripta, 55 (1997) 33-40) by V. G. Pal'chikov, Yu. L. Sokolov, and V. P. Yakovlev
The work is a comments on the article of V. G. Pal'chikov, Yu. L. Sokolov,
and V. P. Yakovlev, devoted to the measurement of the Lamb shift in the
hydrogen atom and published in Physica Scripta, 55 (1997) 33-40.Comment: 4 pages; [email protected]
Photon-Photon Correlations as a Probe of Vacuum Induced Coherence Effects
We present new experimental implications of the effects of vacuum induced
coherence on the photon -photon correlation in the pi-polarized fluorescence in
j = 1/2 to j = 1/2 transition. These effects should be thus observable in
measurements of photon statistics in for example Hg and Ba ion traps.Comment: 7 pages, 6 figures, submitted to Physical Review
Study of quadrupole polarizabilities with combined configuration interaction and coupled-cluster method
The recently developed method combining the configuration interaction and the
coupled-cluster method was demonstrated to provide accurate treatment of
correlation corrections in divalent atomic systems [M.S.Safronova, M.G.Kozlov,
and C.W.Clark, Phys. Rev. Lett. 107, 143006 (2011)]. We have extended this
approach to the calculation of quadrupole polarizabilities alpha_2 and applied
it to evaluate alpha_2 for the ground state of Mg and Mg-like Si^{2+}.
Performing the calculations in three different approximations of increasing
accuracy allowed us to place the upper bounds on the uncertainty of the final
results. The recommended values alpha_2(3s^2 1S0)= 35.86(13) a.u. for Si^{2+}
and alpha_2(3s^2 1S0)= 814(3) a.u. for Mg are estimated to be accurate to
0.37%. Differences in quadrupole polarizability contributions in neutral Mg and
Si^{2+} ion are discussed.Comment: 6 pages, submitted to Phys. Rev.
A Rejoinder on Quaternionic Projective Representations
In a series of papers published in this Journal (J. Math. Phys.), a
discussion was started on the significance of a new definition of projective
representations in quaternionic Hilbert spaces. The present paper gives what we
believe is a resolution of the semantic differences that had apparently tended
to obscure the issues.Comment: AMStex, 6 Page
Successful Supersymmetric Inflation
We reconsider the problems of cosmological inflation in effective
supergravity theories. A singlet field in a hidden sector is demonstrated to
yield an acceptable inflationary potential, without fine tuning. In the
simplest such model, the requirement of generating the microwave background
anisotropy measured by COBE fixes the inflationary scale to be about
GeV, implying a reheat temperature of order GeV. This is low enough to
solve the gravitino problem but high enough to allow baryogenesis after
inflation. Such consistency requires that the generation of gravitational waves
be negligible and that the spectrum of scalar density perturbations depart
significantly from scale-invariance, thus improving the fit to large-scale
structure in an universe dominated by cold dark matter. We also consider the
problems associated with gravitino production through inflaton decay and with
other weakly coupled fields such as the moduli encountered in (compactified)
string theories.Comment: 27 pages (LaTeX) including 1 embedded (PostScript) figure. Revised to
include a fuller discussion of initial conditions (leading to "eternal"
inflation) and the role of moduli; some reordering of sections for greater
clarity. Accepted for publication in Nuclear Physics
Measure valued solutions of sub-linear diffusion equations with a drift term
In this paper we study nonnegative, measure valued solutions of the initial
value problem for one-dimensional drift-diffusion equations when the nonlinear
diffusion is governed by an increasing function with . By using tools of optimal transport, we will show
that this kind of problems is well posed in the class of nonnegative Borel
measures with finite mass and finite quadratic momentum and it is the
gradient flow of a suitable entropy functional with respect to the so called
-Wasserstein distance. Due to the degeneracy of diffusion for large
densities, concentration of masses can occur, whose support is transported by
the drift. We shall show that the large-time behavior of solutions depends on a
critical mass , which can be explicitely characterized in terms of
and of the drift term. If the initial mass is less then ,
the entropy has a unique minimizer which is absolutely continuous with respect
to the Lebesgue measure. Conversely, when the total mass of the solutions
is greater than the critical one, the steady state has a singular part in which
the exceeding mass is accumulated.Comment: 30 page
- …