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Gravity And Bf Theory Defined In Bounded Regions, V. Husain, Seth Major Sep 1997

Gravity And Bf Theory Defined In Bounded Regions, V. Husain, Seth Major

Articles

We study Einstein gravity in a finite spatial region. By requiring a well-defined variational principle, we identify all local boundary conditions, derive surface observables, and compute their algebra. The observables arise as induced surface terms, which contribute to a non-vanishing Hamiltonian. Unlike the asymptotically flat case, we find that there are an infinite number of surface observables. We give a similar analysis for SU(2) BF theory.


On The Stark Broadening Parameters Of The Two Nii Spectral Lines Of The 3d-4f Transition, Vladimir Milosavljevic, Stevan Djenize Jun 1997

On The Stark Broadening Parameters Of The Two Nii Spectral Lines Of The 3d-4f Transition, Vladimir Milosavljevic, Stevan Djenize

Articles

Stark parameters (width and shift) of two singly ionized nitrogen spectral lines, that belong to 3d-4f transition have been measured in a linear pulsed, low pressure, arc discharge in the nitrogen-oxygen plasma at a 54000 K electron temperature and at a 2.8×10 23 m−3 electron density. The measured values have been compared to the existing experimental and calculated data


Diffraction From Polarization Holographic Gratings With Surface Relief In Side-Chain Azobenzene Polyesters, Izabela Naydenova, Ludmila Nikolova, Todor Todorov, N.C.R. Holme, P.S. Ramanujam, S. Hvilsted Jan 1997

Diffraction From Polarization Holographic Gratings With Surface Relief In Side-Chain Azobenzene Polyesters, Izabela Naydenova, Ludmila Nikolova, Todor Todorov, N.C.R. Holme, P.S. Ramanujam, S. Hvilsted

Articles

We investigate the polarization properties of holographic gratings in side-chain azobenzene polyesters in which an anisotropic grating that is due to photoinduced linear and circular birefringence is recorded in the volume of the material and a relief grating appears on the surface. A theoretical model is proposed to explain the experimental results, making it possible to understand the influence of the different photoinduced effects. It is shown that at low intensity the polarization properties of the diffraction at these gratings are determined by the interaction of the linear and circular photobirefringences, and at larger intensity the influence of the surface …


Describing Ideals Of Endomorphism Rings, Brendan Goldsmith, Simone Pabst Jan 1997

Describing Ideals Of Endomorphism Rings, Brendan Goldsmith, Simone Pabst

Articles

No abstract available.