30,082 research outputs found
Thermodynamics of Extended Bodies in Special Relativity
Relativistic thermodynamics is generalized to accommodate four dimensional
rotation in a flat spacetime. An extended body can be in equilibrium when its
each element moves along a Killing flow. There are three types of basic Killing
flows in a flat spacetime, each of which corresponds to translational motion,
spatial rotation, and constant linear acceleration; spatial rotation and
constant linear acceleration are regarded as four dimensional rotation.
Translational motion has been mainly investigated in the past literature of
relativistic thermodynamics. Thermodynamics of the other two is derived in the
present paper.Comment: 8 pages, no figur
Discriminating Minimal SUGRA and Minimal Gauge Mediation Models at the Early LHC
Among various supersymmetric (SUSY) standard models, the gravity mediation
model with a neutralino LSP and the gauge mediation model with a very light
gravitino are attractive from the cosmological view point. These models have
different scales of SUSY breaking and their underlying physics in high energy
is quite different. However, if the sparticles' decay into the gravitino is
prompt in the latter case, their collider signatures can be similar: multiple
jets and missing transverse momentum. In this paper, we study the
discrimination between these models in minimal cases at the LHC based on the
method using the significance variables in several different modes and show the
discrimination is possible at a very early stage after the discovery.Comment: 29 pages, 3 figures, captions improved, typos corrected, appendix
added, version published in JHE
Electron paramagnetic resonance, optical absorption and Raman spectral studies on a pyrite/chalcopyrite mineral
Pyrite and chalcopyrite mineral samples from Mangampet barite mine, Kadapa, Andhra Pradesh, India are used in the present study. XRD data indicate that the pyrite mineral has a face centered cubic lattice structure with lattice constant 5.4179 Å. Also it possesses an average particle size of 91.9 nm. An EPR study on the powdered samples confirms the presence of iron in pyrite and iron and Mn(II) in chalcopyrite. The optical absorption spectrum of chalcopyrite indicates presence of copper which is in a distorted octahedral environment. NIR results confirm the presence of water fundamentals and Raman spectrum reveals the presence of water and sulfate ions
Mechanism of CDW-SDW Transition in One Dimension
The phase transition between charge- and spin-density-wave (CDW, SDW) phases
is studied in the one-dimensional extended Hubbard model at half-filling. We
discuss whether the transition can be described by the Gaussian and the
spin-gap transitions under charge-spin separation, or by a direct CDW-SDW
transition. We determine these phase boundaries by level crossings of
excitation spectra which are identified according to discrete symmetries of
wave functions. We conclude that the Gaussian and the spin-gap transitions take
place separately from weak- to intermediate-coupling region. This means that
the third phase exists between the CDW and the SDW states. Our results are also
consistent with those of the strong-coupling perturbative expansion and of the
direct evaluation of order parameters.Comment: 5 pages(REVTeX), 5 figures(EPS), 1 table, also available from
http://wwwsoc.nacsis.ac.jp/jps/jpsj/1999/p68a/p68a42/p68a42h/p68a42h.htm
Localization length of a soliton from a non-magnetic impurity in a general double-spin-chain model
A localization length of a free-spin soliton from a non-magnetic impurity is
deduced in a general double-spin-chain model ( model). We have
solved a variational problem which employs the nearest-neighbor singlet-dimer
basis. The wave function of a soliton is expressed by the Airy function, and
the localization length is found to obey a power law of the
dimerization with an exponent -1/3; .
This explains why NaV_2O_5 does not show the antiferromagnetic order, while
CuGeO_3 does by impurity doping. When the gap exists by the bond-dimerization,
a soliton is localized and no order is expected. Contrary, there is a
possibility of the order when the gap is mainly due to frustration.Comment: 4 pages, REVTeX, Figures are in eps-file
Enhanced Polarized Emission from the One-Parsec-Scale Hotspot of 3C 84 as a Result of the Interaction with Clumpy Ambient Medium
We present Very Long Baseline Array polarimetric observations of the
innermost jet of 3C84 (NGC1275) at 43GHz. A significant
polarized emission is detected at the hotspot of the innermost re-started jet,
which is located 1 pc south from the radio core. While the previous
report presented a hotspot at the southern end of the western limb, the hotspot
location has been moved to the southern end of the eastern limb. Faraday
rotation is detected within an entire bandwidth of the 43-GHz band. The
measured rotation measure (RM) is at most
(6.31.9)radm and might be slightly time
variable on the timescale of a month by a factor of a few. Our measured RM and
the RM previously reported by the CARMA and SMA observations cannot be
consistently explained by the spherical accretion flow with a power-law
profile. We propose that a clumpy/inhomogeneous ambient medium is responsible
for the observed rotation measure. Using equipartition magnetic field, we
derive the electron density of cm. Such an electron
density is consistent with the cloud of narrow line emission region around the
central engine. We also discuss the magnetic field configuration from black
hole scale to pc scale and the origin of low polarization.Comment: 8 pages, 8 figures, accepted for publication in Ap
Classical and quantum evolution of non-isentropic hot singular layers in finite-temperature general relativity
The spherically symmetric layer of matter is considered within the frameworks
of general relativity. We perform generalization of the already known theory
for the case of nonconstant surface entropy and finite temperature. We also
propose the minisuperspace model to determine the behaviour of temperature
field and perform the Wheeler-DeWitt quantization.Comment: final version, published in GRG as a lette
- …