19,912 research outputs found
Higgs Boson in RG running Inflationary Cosmology
An intriguing hypothesis is that gravity may be non-perturbatively
renormalizable via the notion of asymptotic safety. We show that the Higgs
sector of the SM minimally coupled to asymptotically safe gravity can generate
the observed near scale-invariant spectrum of the Cosmic Microwave Background
through the curvaton mechanism. The resulting primordial power spectrum places
an upper bound on the Higgs mass, which for finely tuned values of the curvaton
parameters, is compatible with the recently released Large Hadron Collider
data.Comment: 7 pages, no figur
The resultant parameters of effective theory
This is the 4-th paper in the series devoted to a systematic study of the
problem of mathematically correct formulation of the rules needed to manage an
effective field theory. Here we consider the problem of constructing the full
set of essential parameters in the case of the most general effective
scattering theory containing no massless particles with spin J > 1/2. We
perform the detailed classification of combinations of the Hamiltonian coupling
constants and select those which appear in the expressions for renormalized
S-matrix elements at a given loop order.Comment: 21 pages, 4 LaTeX figures, submitted to Phys. Rev.
II. The Standard Model in the Isotopic Foldy-Wouthuysen Representation without Higgs Bosons in the Fermion Sector. Spontaneous Breaking of Parity and "Dark Matter" Problems
The Standard Model with massive fermions is formulated in the isotopic
Foldy-Wouthuysen representation. SU(2)xU(1) - invariance of the theory in this
representation is independent of whether fermions possess mass or not, and,
consequently, it is not necessary to introduce interactions between Higgs
bosons and fermions. The study discusses a possible relation between
spontaneous breaking of parity in the isotopic Foldy-Wouthuysen representation
and the composition of elementary particles of "dark matter".Comment: 12 page
Relaxing Lorentz invariance in general perturbative anomalies
We analyze the role of Lorentz symmetry in the perturbative non-gravitational
anomalies for a single family of fermions. The theory is assumed to be
translational invariant, power-counting renormalizable and based on a local
action, but is allowed to have general Lorentz violating operators. We study
the conservation of global and gauge currents associate with general internal
symmetry groups and find, by using a perturbative approach, that Lorentz
symmetry does not participate in the clash of symmetries that leads to the
anomalies. We first analyze the triangle graphs and prove that there are
regulators for which the anomalous part of the Ward identities exactly
reproduces the Lorentz invariant case. Then we show, by means of a regulator
independent argument, that the anomaly cancellation conditions derived in
Lorentz invariant theories remain necessary ingredients for anomaly freedom.Comment: 18 pages, 1 figure. Few comments added. Article published in Physical
Review
Gravitational power from cosmic string loops with many kinks
We investigate the effect of a large number of kinks on the gravitational
power radiated by cosmic string loops. We show that the total power radiated by
a loop with N left-moving and right-moving kinks is proportional to N and
increases with the typical kink angle. We then apply these results to loops
containing junctions which give rise to a proliferation of the number of sharp
kinks. We show that the time of gravitational decay of these loops is smaller
than previously assumed. In light of this we revisit the gravitational wave
burst predictions from a network containing such loops. We find there is no
parameter regime in which the rate of individual kink bursts is enhanced with
respect to standard networks. By contrast, there remains a region of parameter
space for which the kink-kink bursts dominate the stochastic background.
Finally, we discuss the order of magnitude of the typical number of sharp kinks
resulting from kink proliferation on loops with junctions.Comment: 20 pages, 1 figur
Perturbatively Defined Effective Classical Potential in Curved Space
The partition function of a quantum statistical system in flat space can
always be written as an integral over a classical Boltzmann factor \exp[
-\beta V^{\rm eff cl({\bf x}_0)], where V^{\rm eff cl({\bf x}_0) is the
so-called effective classical potential containing the effects of all quantum
fluctuations. The variable of integration is the temporal path average {\bf
x_0\equiv \beta ^{-1}\int_0^ \beta d\tau {\bf x}(\tau). We show how to
generalize this concept to paths in curved space with metric
g_{\mu \nu (q), and calculate perturbatively the high-temperature expansion
of V^{\rm eff cl(q_0). The requirement of independence under coordinate
transformations introduces subtleties in the
definition and treatment of the path average , and covariance is
achieved only with the help of a suitable Faddeev-Popov procedure.Comment: Author Information under
http://www.physik.fu-berlin.de/~kleinert/institution.html . Latest update of
paper (including all PS fonts) at
http://www.physik.fu-berlin.de/~kleinert/33
Inflation in asymptotically safe f(R) theory
We discuss the existence of inflationary solutions in a class of
renormalization group improved polynomial f(R) theories, which have been
studied recently in the context of the asymptotic safety scenario for quantum
gravity. These theories seem to possess a nontrivial ultraviolet fixed point,
where the dimensionful couplings scale according to their canonical
dimensionality. Assuming that the cutoff is proportional to the Hubble
parameter, we obtain modified Friedmann equations which admit both power law
and exponential solutions. We establish that for sufficiently high order
polynomial the solutions are reliable, in the sense that considering still
higher order polynomials is very unlikely to change the solution.Comment: Presented at 14th Conference on Recent Developments in Gravity: NEB
14, Ioannina, Greece, 8-11 Jun 201
Resolving the Degeneracy: Experimental tests of the New Self Creation Cosmology and a heterodox prediction for Gravity Probe B
The new theory of Self Creation Cosmology has been shown to yield a
concordant cosmological solution that does not require inflation, exotic
non-baryonic Dark matter or Dark Energy to fit observational constraints. In
vacuo there is a conformal equivalence between this theory and canonical
General Relativity and as a consequence an experimental degeneracy exists as
the two theories predict identical results in the standard tests. However,
there are three definitive experiments that are able to resolve this degeneracy
and distinguish between the two theories. Here these standard tests and
definitive experiments are described. One of the definitive predictions, that
of the geodetic precession of a gyroscope, has just been measured on the
Gravity Probe B satellite, which is at the present time of writing in the data
processing stage. This is the first opportunity to falsify Self Creation
Cosmology. The theory predicts a 'frame-dragging' result equal to GR but a
geodetic precession of only 2/3 the GR value. When applied to the Gravity Probe
B satellite, Self Creation Cosmology predicts an E-W
gravitomagnetic/frame-dragging precession, equal to that of GR, of 40.9
milliarcsec/yr but a -S gyroscope (geodetic + Thomas) precession of just 4.4096
arcsec/yr.Comment: LaTex, 15 pages. Correction of the prediction of the GP-B geodetic
measurement to 4.4096 arcsec/y
Papapetrou Energy-Momentum Tensor for Chern-Simons Modified Gravity
We construct a conserved, symmetric energy-momentum (pseudo-)tensor for
Chern-Simons modified gravity, thus demonstrating that the theory is Lorentz
invariant. The tensor is discussed in relation to other gravitational
energy-momentum tensors and analyzed for the Schwarzschild, Reissner-Nordstrom,
and FRW solutions. To our knowledge this is the first confirmation that the
Reissner-Nordstrom and FRW metrics are solutions of the modified theory.Comment: 8 pages; typos corrected, references fixed, some calculations
shortene
A Finslerian version of 't Hooft Deterministic Quantum Models
Using the Finsler structure living in the phase space associated to the
tangent bundle of the configuration manifold, deterministic models at the
Planck scale are obtained. The Hamiltonian function are constructed directly
from the geometric data and some assumptions concerning time inversion
symmetry. The existence of a maximal acceleration and speed is proved for
Finslerian deterministic models. We investigate the spontaneous symmetry
breaking of the orthogonal symmetry SO(6N) of the Hamiltonian of a
deterministic system. This symmetry break implies the non-validity of the
argument used to obtain Bell's inequalities for spin states. It is introduced
and motivated in the context of Randers spaces an example of simple 't Hooft
model with interactions.Comment: 25 pages; no figures. String discussion deleted. Some minor change
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