5,677 research outputs found
Inertia of Heat in Advective Accretion Disks around Kerr Black Holes
In the innermost region of the advective accretion disk orbiting a black hole
of high spin, the inertia of heat stored in the accreting gas is comparable to
that of the gas rest mass itself. Accounting for this effect, we derive
additional terms in the disk structure equations, and show that the heat
inertia plays a significant role in the global energy conservation and dynamics
of accretion in the relativistic advective disks.Comment: 6 pages, Latex, submitted to ApJ
Once more on extra quark-lepton generations and precision measurements
Precision measurements of -boson parameters and -boson and -quark
masses put strong constraints on non singlet New Physics. We
demonstrate that one extra generation passes electroweak constraints even when
all new particle masses are well above their direct mass bounds.Comment: Dedicated to L.B. Okun's 80th birthda
On the numerical closeness of the effective phenomenological electroweak mixing angle and the \MS parameter
It happens that and are equal with 0.1% accuracy, though
they are split by radiative corrections and a natural estimate for their
difference is 1%. This degeneracy occurs only for value close to
170\GeV, so no deep physical reason can be attributed to it. However, another
puzzle of the Standard Model, the degeneracy of s_\Eff^2 and , is not
independent of the previous one since a good physical reason exists for
s_\Eff^2 and degeneracy. We present explicit formulas which relate
these three angles.Comment: 10 pages, latex, 3 figures included; published on MPLA. A few
numerical estimates are improved; journal-ref is adde
New global stability estimates for the Gel'fand-Calderon inverse problem
We prove new global stability estimates for the Gel'fand-Calderon inverse
problem in 3D. For sufficiently regular potentials this result of the present
work is a principal improvement of the result of [G. Alessandrini, Stable
determination of conductivity by boundary measurements, Appl. Anal. 27 (1988),
153-172]
Two-dimensional algebro-geometric difference operators
A generalized inverse problem for a two-dimensional difference operator is
introduced. A new construction of the algebro-geometric difference operators of
two types first considered by I.M.Krichever and S.P.Novikov is proposedComment: 11 pages; added references, enlarged introduction, rewritten abstrac
Geometry and Statistics of Cosmic Microwave Polarization
Geometrical and statistical properties of polarization of CMB are analyzed.
Singular points of the vector field which describes CMB polarization are found
and classified. Statistical distribution of the singularities is studied. A
possible signature of tensor perturbations in CMB polarization is discussed.
For a further analysis of CMB statistics Minkowski functionals are used, which
present a technically simple method to search for deviations from a Gaussian
distribution.Comment: 37 pages, 5 figures, submitted in Int.J.Mod.Phys.
Mass of the higgs versus fourth generation masses
The predicted value of the higgs mass is analyzed assuming the
existence of the fourth generation of leptons () and quarks ().
The steep and flat directions are found in the five-dimensional parameter
space: , , , , . The LEPTOP fit of the precision
electroweak data is compatible (in particular) with GeV, GeV, GeV, GeV, and GeV. The quality of fits drastically improves when the data on b- and
c-quark asymmetries and new NuTeV data on deep inelastic scattering are
ignored.Comment: 8 pages, 4 figure
Diagrammatic calculation of energy spectrum of quantum impurity in degenerate Bose-Einstein condensate
In this paper we considered a quantum particle moving through delute
Bose-Einstein condensate at zero temperature. In our formulation the impurity
particle interacts with the gas of uncoupled Bogoliubov's excitations. We
constructed the perturbation theory for the Green's function of the impurity
particle with respect to the impurity-condensate interaction employing the
coherent-state path integral approach. The perturbative expansion for the
Green's function is resumed into the expansion for its poles with the help of
the diagrammatic technique developed in this work. The dispersion relation for
the impurity clothed by condensate excitations is obtained and effective mass
is evaluated beyond the Golden rule approximation
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