20,324 research outputs found
Applications of ISES for coastal zone studies
In contrast to the discipline- and process-oriented topics addressed, coastal zone studies are defined geographically by the special circumstances inherent in the interface between land and water. The characteristics of coastal zones which make them worthy of separate consideration are: (1) the dynamic nature of natural and anthropogenic processes taking place; (2) the relatively restricted spatial domain of the narrow land/water interface; and (3) the large proportion of the Earth's population living within coastal zones, and the resulting extreme pressure on natural and human resources. These characteristics place special constraints and priorities on remote sensing applications, even though the applications themselves bear close relation to those addressed by other elements of this report (e.g., oceans, ice, vegetation/land use). The discussion which follows first describes the suite of remote sensing activities relevant to coastal zone studies. Potential Information Sciences Experiment System (ISES) experiments will then be addressed within two general categories: applications of real-time data transmission and applications of onboard data acquisition and processing
Hall-Littlewood polynomials and characters of affine Lie algebras
The Weyl-Kac character formula gives a beautiful closed-form expression for
the characters of integrable highest-weight modules of Kac-Moody algebras. It
is not, however, a formula that is combinatorial in nature, obscuring
positivity. In this paper we show that the theory of Hall-Littlewood
polynomials may be employed to prove Littlewood-type combinatorial formulas for
the characters of certain highest weight modules of the affine Lie algebras
C_n^{(1)}, A_{2n}^{(2)} and D_{n+1}^{(2)}. Through specialisation this yields
generalisations for B_n^{(1)}, C_n^{(1)}, A_{2n-1}^{(2)}, A_{2n}^{(2)} and
D_{n+1}^{(2)} of Macdonald's identities for powers of the Dedekind
eta-function. These generalised eta-function identities include the
Rogers-Ramanujan, Andrews-Gordon and G\"ollnitz-Gordon q-series as special,
low-rank cases.Comment: 33 pages, proofs of several conjectures from the earlier version have
been include
Conversion Efficiencies of Heteronuclear Feshbach Molecules
We study the conversion efficiency of heteronuclear Feshbach molecules in
population imbalanced atomic gases formed by ramping the magnetic field
adiabatically. We extend the recent work [J. E. Williams et al., New J. Phys.,
8, 150 (2006)] on the theory of Feshbach molecule formations to various
combinations of quantum statistics of each atomic component. A simple
calculation for a harmonically trapped ideal gas is in good agreement with the
recent experiment [S. B. Papp and C. E. Wieman, Phys. Rev. Lett., 97, 180404
(2006)] without any fitting parameters. We also give the conversion efficiency
as an explicit function of initial peak phase space density of the majority
species for population imbalanced gases. In the low-density region where
Bose-Einstein condensation does not appear, the conversion efficiency is a
monotonic function of the initial peak phase space density, but independent of
statistics of a minority component. The quantum statistics of majority atoms
has a significant effect on the conversion efficiency. In addition,
Bose-Einstein condensation of an atomic component is the key element
determining the maximum conversion efficiency.Comment: 46 pages, 32 figure
- …