63,410 research outputs found
The effect of a light radion on the triviality bound on higgs mass
In this paper we study how the triviality bound on higgs mass in the context
of the SM is modified by a light stabilized radion of the Goldberger-Wise
variety. Our approach is inherently perturbative. Including the radion
contribution to \bt(\l) and \bt(g_t) to one loop we evolve the higgs self
coupling \l from the cut off \L(=\vphi) down to the EW scale .
The triviality bound is obtained by requiring that \l(\L) = \sqrt{4 \pi}
which is the perturbative limit. We also study the effect of small changes in
the UVBC on the triviality bound both in the presence and absence of a light
radion.Comment: 9 pages, latex, 2 eps figure
An alternative construction of the positive inner product for pseudo-Hermitian Hamiltonians: Examples
This paper builds on our earlier proposal for construction of a positive
inner product for pseudo-Hermitian Hamiltonians and we give several examples to
clarify our method. We show through the example of the harmonic oscillator how
our construction applies equally well to Hermitian Hamiltonians which form a
subset of pseudo-Hermitian systems. For finite dimensional pseudo-Hermitian
matrix Hamiltonians we construct the positive inner product (in the case of
matrices for both real as well as complex eigenvalues). When the
quantum mechanical system cannot be diagonalized exactly, our construction can
be carried out perturbatively and we develop the general formalism for such a
perturbative calculation systematically (for real eigenvalues). We illustrate
how this general formalism works out in practice by calculating the inner
product for a couple of symmetric quantum mechanical theories.Comment: 9 pages, revte
Constraints on neutrino and dark radiation interactions using cosmological observations
Observations of the cosmic microwave background (CMB) and large-scale
structure (LSS) provide a unique opportunity to explore the fundamental
properties of the constituents that compose the cosmic dark radiation
background (CDRB), of which the three standard neutrinos are thought to be the
dominant component. We report on the first constraint to the CDRB rest-frame
sound speed, ceff^2, using the most recent CMB and LSS data. Additionally, we
report improved constraints to the CDRB viscosity parameter, cvis^2. For a
non-interacting species, these parameters both equal 1/3. Using current data we
find that a standard CDRB, composed entirely of three non-interacting neutrino
species, is ruled out at the 99% confidence level (C.L.) with ceff^2 = 0.30
+0.027 -0.026 and cvis^2 = 0.44 +0.27 -0.21 (95% C.L.). We also discuss how
constraints to these parameters from current and future observations (such as
the Planck satellite) allow us to explore the fundamental properties of any
anomalous radiative energy density beyond the standard three neutrinos.Comment: 6 pages, 3 figures, comments welcome; v2: updated with SPT data,
corrected minor typos; v3: version accepted for publication in PR
Topological Structure of the Vacuum, Cosmological Constant and Dark Energy
In this review we present a theory of cosmological constant and Dark Energy
(DE), based on the topological structure of the vacuum. The Multiple Point
Principle (MPP) is reviewed. It demonstrates the existence of the two vacua
into the SM. The Froggatt-Nielsen's prediction of the top-quark and Higgs
masses is given in the assumption that there exist two degenerate vacua in the
SM. This prediction was improved by the next order calculations. We also
considered B.G. Sidharth's theory of cosmological constant based on the
non-commutative geometry of the Planck scale space-time, what gives an
extremely small DE density providing the accelerating expansion of the
Universe. Theory of two degenerate vacua - the Planck scale phase and
Electroweak (EW) phase - also is reviewed, topological defects in these vacua
are investigated, also the Compton wavelength phase suggested by B.G. Sidharth
was discussed. A general theory of the phase transition and the problem of the
vacuum stability in the SM is reviewed. Assuming that the recently discovered
at the LHC new resonance with mass GeV is a new scalar
bound state , earlier predicted by C.D. Froggatt, H.B. Nielsen
and L.V. Laperashvili, we try to provide the vacuum stability in the SM and
exact accuracy of the MPP.Comment: 37 pages and 7 figures. arXiv admin note: text overlap with
arXiv:1601.03231; text overlap with arXiv:1302.2716 by other author
Graviweak Unification, Invisible Universe and Dark Energy
We consider a Graviweak Unification model with the assumption of the
existence of the hidden (invisible) sector of our Universe parallel to the
visible world. This Hidden World (HW) is assumed to be a Mirror World (MW) with
broken mirror parity. We start with a diffeomorphism invariant theory of a
gauge field valued in a Lie algebra g, which is broken spontaneously to the
direct sum of the spacetime Lorentz algebra and the Yang-Mills algebra: -- in
the ordinary world, and -- in the hidden world. Using
an extension of the Plebanski action for general relativity, we recover the
actions for gravity, SU(2) Yang-Mills and Higgs fields in both (visible and
invisible) sectors of the Universe, and also the total action. After symmetry
breaking, all physical constants, including the Newton's constants,
cosmological constants, Yang-Mills couplings, and other parameters, are
determined by a single parameter presented in the initial action, and by
the Higgs VEVs. The Dark Energy problem of this model predicts a too large
supersymmetric breaking scale ( GeV), which is not within
the reach of the LHC experiments.Comment: 20 pages. arXiv admin note: substantial text overlap with
arXiv:1004.4866 by other author
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