1,251 research outputs found
The surface density of holographic entropy
On the basis of postulates for the holographic description of gravity and the
introduction of entropic force, for static sources we derive the universal law:
the entropy of a holographic screen is equal to quarter of its area in the
Planck system of units.Comment: 6 page
Natural scale of cosmological constant in seesaw mechanism with broken SUSY
The cosmological constant is inherently determined by the scale of breaking
down supersymmetry in the mechanism of seesaw fluctuations of two
vacuum-states.Comment: 4 pages, revtex4 class, reference adde
Properties of potential modelling three benchmarks: the cosmological constant, inflation and three generations
We argue for a model of low-energy correction to the inflationary potential
as caused by the gauge-mediated breaking down the supersymmetry at the scale of
\mu_\textsc{x}\sim 10^4 GeV, that provides us with the seesaw mechanism of
thin domain wall fluctuations in the flat vacuum. The fluctuations are
responsible for the vacuum with the cosmological constant at the scale of
eV suppressed by the Planckian mass
via \mu_\Lambda\sim\mu_\textsc{x}^2/m_\mathtt{Pl}. The appropriate vacuum
state is occupied after the inflation with quartic coupling constant
\lambda\sim\mu_\textsc{x}/m_\mathtt{Pl}\sim 10^{-14} inherently related with
the bare mass scale of \widetilde m\sim\sqrt{\mu_\textsc{x}m_\mathtt{Pl}}\sim
10^{12} GeV determining the thickness of domain walls . Such the parameters of potential are still marginally
consistent with the observed inhomogeneity of matter density in the Universe.
The inflationary evolution suggests the vacuum structure compatible with three
fermionic generations of matter as well as with observed hierarchies of masses
and mixing in the Standard Model.Comment: 12 pages, 1 figure, revtex4 class, references adde
Renormalization group analysis of cosmological constraint on the mass of Higgs scalar
The Higgs boson of Standard Model, minimally coupled to the gravitation, is
not able to produce the inflation of early Universe if its mass exceeds the
threshold value, which is equal to m_H^{min} = 142 GeV in the tree
approximation for the scalar potential. Two-loop corrections modify the
estimate as m_H^{min} = 150 \pm 3 GeV, so that higher-order corrections of
perturbation theory are completely under control, though they are numerically
important in respect of experimental searches.Comment: 6 page
The holographic screen at low temperatures
A permissible spectrum of transverse vibrations for the holographic screen
modifies both a distribution of thermal energy over bits at low temperatures
and the law of gravitation at small accelerations of free fall in agreement
with observations of flat rotation curves in spiral galaxies. This modification
relates holographic screen parameters in de Sitter space-time with the Milgrom
acceleration in MOND.Comment: 7 pages, 1 figur
Decoupling of Higgs boson from the inflationary stage of Universe evolution
The constraint on the mass of Higgs field in the Standard Model at the
minimal interaction with the gravity is derived in the form of lower bound
GeV by the strict requirement of decoupling the Higgs boson from the
inflation of early Universe: the inflation produced by the Higgs scalar could
crucially destroy visible properties of large scale structure of Universe,
while the large mass makes the Higgs particle not able to produce the inflation
and shifts its cosmological role into the region of quantum gravity.Comment: 6 pages, svjour class, comments and reference adde
Coherently controlling Raman-induced grating in atomic media
We consider dynamically controllable periodic structures, called Raman
induced gratings, in three- and four-level atomic media, resulting from Raman
interaction in a standing-wave pump. These gratings are due to periodic spatial
modulation of the Raman nonlinearity and fundamentally differ from the ones
based on electromagnetically induced transparency. The transmission and
reflection spectra of such gratings can be simultaneously amplified and
controlled by varying the pump field intensity. It is shown that a transparent
medium with periodic spatial modulation of the Raman gain can be opaque near
the Raman resonance and yet at the same time it can be a non-linear amplifying
mirror. We also show that spectral properties of the Raman induced grating can
be controlled with the help of an additional weak control field.Comment: 7 pages, 12 figure
Tamm Plasmon in a Structure with the Nanocomposite Containing Spheroidal Core-Shell Particles
Spectral peculiarities of the structure consisting of a photonic crystal
coated with a nanocomposite have been investigated. The nanocomposite used
contains spheroidal nanoparticles with a dielectric core and a metallic shell,
which are uniformly dispersed in a transparent matrix. The spectral
manifestation of the observed Tamm plasmon polariton and Fabry--Perot mode has
been examined. A significant polarization sensitivity of the spectra upon
variation in the nanoparticle shape has been demonstrated. The dispersion
curves presented for the Tamm plasmon polariton and Fabry--Perot mode are shown
to be in good agreement with the spectra obtained by the transfer matrix
method
Tunable Hybrid Tamm-microcavity states
Spectral manifestations of hybrid Tamm-microcavity modes in a 1D photonic
crystal bounded with a silver layer and containing a nematic liquid crystal
layer working as a microcavity have been studied using numerical simulation. It
is demonstrated that the hybrid modes can be effectively tuned owing to the
high sensitivity of the liquid crystal to the temperature and external electric
field variations. It is established that the effect of temperature on the
transmission spectrum of the investigated structure is most pronounced at the
point of the phase transition of the liquid crystal to the isotropic state,
where the refractive index jump is observed
Super-long life time for 2D cyclotron spin-flip excitons
An experimental technique for the indirect manipulation and detection of
electron spins entangled in two-dimensional magnetoexcitons has been developed.
The kinetics of the spin relaxation has been investigated. Photoexcited
spin-magnetoexcitons were found to exhibit extremely slow relaxation in
specific quantum Hall systems, fabricated in high mobility GaAs/AlGaAs
structures, namely, the relaxation time reaches values over one hundred
microseconds. A qualitative explanation of this spin-relaxation kinetics is
presented. Its temperature and magnetic field dependencies are discussed within
the available theoretical framework.Comment: 5 pages, 3 figure
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