99 research outputs found
Potential for the slow-roll inflation, mass scale hierarchy and Dark Energy from the Type IIA supergravity
The magnetic fluxbrane solution with a strongly warped throat is studied in
the Type IIA supergravity theory with co-dimension one local source which
surves as -symmetric UV boundary of the throat. Overall volume of extra
space is stabilized since introduction of the local source breaks the no-scale
structure of the theory and evades the no-go theorem. Radion field is defined
as the position of UV boundary "moved" from its stable value fixed by the
anisotropic Israel junction conditions. Analytical expression for the radion
effective potential is received. Potential decreases exponentially (exponent is
equal to 0,21 in Planck units) in the slow-roll region and apparently meets
other demands of the early inflation. Reissner-Nordstrom type deformation of
the elementary fluxbrane solution permits to construct the IR end of the throat
and results in tiny positive non-zero value of the radion potential in its
extremal point seen today as Dark Energy . Expressions for the
mass scale hierarchy and for the "acceleration hierarchy" received in the paper
give the physically interesting relation between two hierarchies: .Comment: 32 pages, Late
Higgs mechanism from fluxes and two mass hierarchies in the "fat" throat solution of Type IIA supegravity
Spectra of Kaluza-Klein gauge fields are calculated at the background of the
magnetic fluxbrane throat-like solution of the Type IIA supergravity equations.
Magnetic flux plays the role of Higgs scalar generating the electroweak scale
mass of non-abelian KK gauge field. The same "flux-Higgs" mechanism gives the
scale of the "second mass hierarchy", 0.001 eV, in the spectrum of KK
excitations at the background of the throat deformed in a Reissner-Nordstrom
way. Gauge coupling constants in 4 dimensions are calculated; they prove to be
of the physically sensible values for the EW scale massive modes of the gauge
fields and are extremely small for the long range gauge fields. 5D effective
Action with the flux-generated mass terms of the KK gauge fields associated
with isometries of compactified subspaces is put down, correspondence of the
"classical" KK approach and dual holography approach to the low-dimensional
gauge theories is discussed, and idea of Bootstrap Holography is set forth.Comment: 24 page
II. Calculation of large mass hierarchy from number of extra dimensions
The higher-dimensional generalization of Randall-Sundrum approach with
additional positive curvature -dimensional and Ricci-flat -dimensional
compuct subspaces is considered in pure gravity theory with metric of
space-time and -form potential as basic fields. Introduction of mass
term of -form potential into the action of co-dimension one brane
permits to stabilize brane's position and hence to calculate the value of
Planck/electroweek scales ratio. There are no ad hoc too large or too small
parameters in the theory; calculated mass hierarchy strongly depends on
dimensionalities , of additional subspaces and its observed large value
in 4 dimensions (i.e. for ) is received in particular in (,
) or (, ) space-times.Comment: 11 pages, Late
Calculation of the Observationally Small Cosmological Constant in the Model of Six-Dimensional Warped Brane-Bolt World
In the 6-dimensional model of warped compactification based on the euclidean
AdS Reissner-Nordstrom metric it is possible to escape artificial 4-brane's
stress-energy tensor anistropy necessary for fulfillment of Israel junction
conditions by introducing in 3+1 spacetime of the cosmological constant which
turns out to be ( - Newton's constant) and acquires the value
compatible with observations.Comment: 8 pages, LaTeX-2
Scalar field on AdS: quantum one loop "in one line"
It is shown that quantum one-loop potentials of the bulk fields in the
Randall and Sundrum (RS) model may be immediately expressed in integrals with
use of Barvinsky-Nesterov or equivalently Gelfand-Yaglom methods of calculation
of quantum determinants. Simple expression is obtained for the UV-finite
difference of one-loop quantum energies for two arbitrary values of parameter
of the double-trace asymptotic boundary condition in one-brane and two-brane
RS-models. Compact formula for Schwinger-DeWitt expansion gives values of
induced Planck mass and induced gauge coupling constant in transverse space.
S-DW expansion is plagued by IR-divergences in one-brane RS-model and makes
sense in two-brane model.Comment: 19 pages, Report at the Ginzburg Centennial Conference, Lebedev
Institute, Moscow, 29 May - 03 June 201
"Old" Conformal Bootstrap in the AdS/CFT Context
The Schwinger-Dyson equations for Green functions and 3-vertexes in planar
approximation used 50 years ago in the earlier theory of conformal bootstrap
are written in frames of the AdS/CFT correspondence. The technique of
"Wightman-Witten" diagrams is used in calculations of the bubble bulk diagrams
that permitted to obtain the values of conformal dimensions of primary
operators in two models of the interacting bulk scalar fields which conformal
dimensions obey "extremal" relation. Simple expressions for the four-point tree
"Wightman-Witten" correlators of these primary operators are obtained and
spectra of corresponding Bethe-Salpeter equations are calculated.Comment: 24 page
Sakharov's induced gravity on the AdS background: SM scale as inverse mass parameter of the Schwinger-DeWitt expansion
One loop quantum effective action W of scalar field 'living' on the AdS
background of the Randall-Sundrum model is defined here by now popular way
which excludes bulk UV divergencies; thus induced Planck mass is given not by
the UV regularization parameter, like in Sakharov's pioneer work, but by the
location of the UV-cut of AdS space. Resummation of Schwinger-DeWitt expansion
of the action W is performed by the novel 'auxiliary mass' method. The inverse
mass squared parameter of this expansion is determined by the location of the
'visible' IR-brane of the RS-model. Obtained expression for induced vacuum
energy density coincides with the independently calculated VEV of the
stress-energy tensor. Corresponding potential in 4 dimensions possesses a
non-trivial extremum which hopefully will permit us to stabilize IR brane and
hence to fix the observed small value of mass hierarchy in analogy with the
Coleman-Weinberg mechanism. It is demonstrated that naive equating of values of
the induced Planck mass and vacuum energy density to those of the RS-model
determines otherwise arbitrary constants of the model. A principle of quantum
self-consistency generalizing this approach is proposed.Comment: 26 pages, Latex; Contents and Section 5.4 adde
String theory provides landmarks fixing RS branes' positions: Possibility to deduce large mass hierarchy from small numbers
Two-branes RS-I 5-dimensional model is generalized in higher dimensional
string-induced theory with dilaton and -form field. It is supposed that
"hidden" and "visible" Randall-Sundrum branes are located at the boundaries of
region of space-time where low-energy supergravity description is valid. This
permits to determine mass scale hierarchy which calculated value proves to be
strongly dependent on dimensionalities of subspaces.Comment: 12 pages, Late
Mach's Principle selects 4 space-time dimensions
Bi-tensor kernel in integral form of Einstein equations realizing Mach's idea
of non-existence of empty space-times is taken as an inverse of differential
operator ("Mach operator") defined conventionally as a second variation of
Einstein's gravity Action over contravariant components of metric tensor. The
choice of transverse gauge condition used in this definition does not influence
results of the paper since only transverse and traceless tensor modes written
on different background space-times are studied. Presence of ghosts among modes
of Mach operator invalidates the integral formulation of Einstein equations.
And the demand of absence of these ghosts proves to be a selection rule for
dimensionality of the background space-time. In particular Mach operator
written on De Sitter background or on the background of so called "Einstein
Universe" does not possess tensor ghosts only in 4-dimensions. The similar
demand gives non-trivial formula for dimensionalities of subspaces of the
Freund-Rubin background.Comment: 15 page
I. Calculation of the observed value of large mass hierarchy in modified RS model
In generalized Randall-Sundrum (RS) model with dilaton where bulk potential
is generated by the antisymmetric tensor field the mass term of this field is
introduced into the brane's Action. This permits to stabilize brane's position
and hence to calculate the Planck/electroweek scales ratio which proves to
depend non-analytically on the dilaton-antisymmetric tensor field coupling
constant. The large observed number of mass hierarchy is achieved for the
moderate value of this coupling constant of order 0,3. In the subsequent Paper
II it is shown that the same approach in a higher dimensional theory without
dilaton permits to express mass hierarchy only through number of extra
dimensions.Comment: 10 pages, Late
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