7,455 research outputs found
Distinguished orbits and the L-S category of simply connected compact Lie groups
We show that the Lusternik-Schnirelmann category of a simple, simply
connected, compact Lie group G is bounded above by the sum of the relative
categories of certain distinguished conjugacy classes in G corresponding to the
vertices of the fundamental alcove for the action of the affine Weyl group on
the Lie algebra of a maximal torus of G.Comment: 10 pages, 2 figure
Resonance widths for the molecular predissociation
We consider a semiclassical matrix Schr\"odinger operator of the
form , where
are real-analytic, admits a non degenerate minimum at 0,
is non trapping at energy , and is a symmetric off-diagonal matrix of first-order
pseudodifferential operators with analytic symbols. We also assume that . Then, denoting by the first eigenvalue of -\Delta + \la
V_2"(0)x,x\ra /2, and under some ellipticity condition on and
additional generic geometric assumptions, we show that the unique resonance
of such that (as ) satisfies, where is a symbol with
, is the so-called Agmon distance associated with the
degenerate metric , between 0 and ,
and , are integers that depend on the geometry.Comment: 37 pages, no figur
Ultrafast WDM logic
Ultrafast all-optical logic gates that accept optical inputs in which wavelength designates bit position within the overall byte are proposed and demonstrated. Four-wave mixing is shown to provide a conditional test function that can be used to construct any multi-input logic gate. Polarization provides the logic state for each bit. Implementations that use semiconductor optical amplifiers as the four-wave mixing medium can be monolithic and compact
Spectral logic gates for byte-wide WDM signal processing
We propose a new class of all-optical logic gates based on four-wave mixing, designed to operate on multiwavelength input signals. We demonstrate the XOR function with two 2.5-Gbit/s modulated input signals
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