288 research outputs found
The Normal Form Theorem around Poisson Transversals
We prove a normal form theorem for Poisson structures around Poisson
transversals (also called cosymplectic submanifolds), which simultaneously
generalizes Weinstein's symplectic neighborhood theorem from symplectic
geometry and Weinstein's splitting theorem. Our approach turns out to be
essentially canonical, and as a byproduct, we obtain an equivariant version of
the latter theorem.Comment: 15 pages; v2: the title was changed; v3: proof of Lemma 2 was
include
Morita Invariance of Intrinsic Characteristic Classes of Lie Algebroids
In this note, we prove that intrinsic characteristic classes of Lie
algebroids - which in degree one recover the modular class - behave
functorially with respect to arbitrary transverse maps, and in particular are
weak Morita invariants. In the modular case, this result appeared in
[Kosmann-Schwarzbach Y., Laurent-Gengoux C., Weinstein A., Transform. Groups 13
(2008), 727-755], and with a connectivity assumption which we here show to be
unnecessary, it appeared in [Crainic M., Comment. Math. Helv. 78 (2003),
681-721] and [Ginzburg V.L., J. Symplectic Geom. 1 (2001), 121-169]
Large Amplitude Photocurrent In Photo-emf Experiments In Pure And Doped Absorbing Photorefractive Crystals
We report a mathematical formulation that successfully describes the holographic photocurrent produced in photo-emf experiments, with large oscillation amplitudes, in strongly absorbing photorefractive materials. The large amplitude produces a sensible enhancement of the photocurrent signal and in this way facilitates measurements. Accounting for bulk light absorption of the sample is essential in order to adequately describe the experiment. We measure pure and doped photorefractive Bi12TiO20 (BTO) crystals and show that these data are in excellent agreemnt with theory. From data fitting we are able to determine some material's parameters.4829 II953954Trofimov, G.S., Stepanov, S.I., (1986) Sov. Phys. Solid State, 28, pp. 1559-1562Petrov, M.P., Sokolov, I.A., Stepanov, S.I., Trofimov, G.S., (1990) J. Appl. Phys., 68, pp. 2216-2225Bittner, R., Meerholz, K., Stepanov, S., (1999) Appl. Phys. Lett., 74, pp. 3723-3725Korneev, N.A., Stepanov, S., (1993) J. Appl. Phys., 74, pp. 2736-2741Bryushinin, M.A., Dubrovsky, G.B., Sokolov, L.A., (1999) Appl. Phys. B, 68, pp. 871-87
- …