23,178 research outputs found
A conservative extension of first-order logic and its application to theorem proving
We define a weak second--order extension of first--order logic. We prove a second--order cut elimination theorem for this logic and use this to prove a conservativity and a realisability result. We give applications to formal program development and theorem proving, in particular, in modeling techniques in formal metatheory
Recent Experiments with Bose-Condensed Gases at JILA
We consider a binary mixture of two overlapping Bose-Einstein condensates in
two different hyperfine states of \Rb87 with nearly identical magnetic moments.
Such a system has been simply realized through application of radiofrequency
and microwave radiation which drives a two-photon transition between the two
states. The nearly identical magnetic moments afford a high degree of spatial
overlap, permitting a variety of new experiments. We discuss some of the
conditions under which the magnetic moments are identical, with particular
emphasis placed on the requirements for a time-averaged orbiting potential
(TOP) magnetic trap.Comment: 9 pages, 5 figures; corrected post-publication editio
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