515 research outputs found
Gravitational descendants in symplectic field theory
It was pointed out by Y. Eliashberg in his ICM 2006 plenary talk that the
rich algebraic formalism of symplectic field theory leads to a natural
appearance of quantum and classical integrable systems, at least in the case
when the contact manifold is the prequantization space of a symplectic
manifold. In this paper we generalize the definition of gravitational
descendants in SFT from circle bundles in the Morse-Bott case to general
contact manifolds. After we have shown that for the basic examples of
holomorphic curves in SFT, that is, branched covers of cylinders over closed
Reeb orbits, the gravitational descendants have a geometric interpretation in
terms of branching conditions, we compute the corresponding sequences of
Poisson-commuting functions when the contact manifold is the unit cotangent
bundle of a Riemannian manifold.Comment: 44 pages, no figure
Higher algebraic structures in Hamiltonian Floer theory I
This is the first of two papers devoted to showing how the rich algebraic
formalism of Eliashberg-Givental-Hofer's symplectic field theory (SFT) can be
used to define higher algebraic structures on the symplectic cohomology of open
symplectic manifolds. Using the SFT of Hamiltonian mapping tori we show how to
define a homotopy extension of the well-known Lie bracket on symplectic
cohomology. Apart from discussing applications to the existence of closed Reeb
orbits, we outline how the -structure is conjecturally related via
mirror symmetry to the extended deformation theory of complex structures.Comment: Results of arXiv:1310.6014 got merged into arXiv:1412.2682, now
entitled "Higher algebraic structures in Hamiltonian Floer theory" and
published in Advances in Geometry (DOI: 10.1515/advgeom-2019-0017).
Extensions of other announced results have been turned into an ongoing PhD
thesis projec
Local symplectic field theory
Generalizing local Gromov-Witten theory, in this paper we define a local
version of symplectic field theory. When the symplectic manifold with
cylindrical ends is four-dimensional and the underlying simple curve is regular
by automatic transversality, we establish a transversality result for all its
multiple covers and discuss the resulting algebraic structures
Dual Q-switched laser outputs from a single lasing medium using an intracavity MEMS micromirror array
An intracavity array of individually controlled microelectromechanical system scanning micromirrors was used to actively Q-switch a single side-pumped Nd:YAG gain medium. Two equal power independent laser outputs were simultaneously obtained by separate actuation of two adjacent micromirrors with a combined average output power of 125 mW. Pulse durations of 28 ns FWHM at 8.7 kHz repetition frequency and 34 ns FWHM at 7.9 kHz repetition frequency were observed for the two output beams with beam quality factors M2 of 1.2 and 1.1 and peak powers of 253 W and 232 W, respectively
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