377 research outputs found
Accelerated Detectors and Temperature in (Anti) de Sitter Spaces
We show, in complete accord with the usual Rindler picture, that detectors
with constant acceleration in de Sitter (dS) and Anti de Sitter (AdS)
spaces with cosmological constants measure temperatures , the detector "5-acceleration" in the
embedding flat 5-space. For dS, this recovers a known result; in AdS, where
is negative, the temperature is well defined down to the critical
value , again in accord with the underlying kinematics. The existence
of a thermal spectrum is also demonstrated for a variety of candidate wave
functions in AdS backgrounds.Comment: Latex +2 Fi
Thermalization of the system "3He-aerogel" at 1.5 K
At the present work we propose a new method for studying the processes of
thermodynamic equilibrium setting in the adsorbed 3He film in a porous media.
By this method we have studied the thermalization of the adsorbed 3He on the
silica aerogel surface at the temperature 1.5 K. The process of the
thermodynamic equilibrium setting was controlled by measuring of the pressure
in the experimental cell, the amplitude of the NMR signal and the time of the
nuclear spin-spin and spin-lattice relaxation times of an adsorbed 3He. The
thermodynamic equilibrium setting in the system "adsorbed helium-3 - aerogel"
has the characteristic time 26 min.Comment: 4 figure
Boundary resistance in magnetic multilayers
Quasiclassical boundary conditions for electrochemical potentials at the
interface between diffusive ferromagnetic and non-magnetic metals are derived
for the first time. An expression for the boundary resistance accurately
accounts for the momentum conservation law as well as essential gradients of
the chemical potentials. Conditions are established at which spin-asymmetry of
the boundary resistance has positive or negative sign. Dependence of the spin
asymmetry and the absolute value of the boundary resistance on the exchange
splitting of the conduction band opens up new possibility to estimate spin
polarization of the conduction band of ferromagnetic metals. Consistency of the
theory is checked on existing experimental data.Comment: 8 pages, 3 figures, designed using IOPART styl
- …
