113 research outputs found
Higgs Mass and Gravity Waves in Standard Model False Vacuum Inflation
In previous publications we have proposed that Inflation can be realized in a
second minimum of the Standard Model Higgs potential at energy scales of about
GeV, if the minimum is not too deep and if a mechanism which allows a
transition to the radiation dominated era can be found. This is provided, {\it
e.g.}, by scalar-tensor gravity models or hybrid models. Using such ideas we
had predicted the Higgs boson mass to be of about GeV, which has
been confirmed by the LHC, and that a possibly measurable amount of gravity
waves should be produced. Using more refined recent theoretical calculations of
the RGE we show that such scenario has the right scale of Inflation only for
small Higgs mass, lower than about 124 GeV, otherwise gravity waves are
overproduced. The precise value is subject to some theoretical error and to
experimental errors on the determination of the strong coupling constant. Such
an upper bound corresponds also to the recent claimed measurement by BICEP2 of
the scale of inflation through primordial tensor modes. Finally we show that
introducing a moderately large non-minimal coupling for the Higgs field the
bound can shift to larger values and be reconciled with the LHC measurements of
the Higgs mass.Comment: 6 pages, 4 figure
Dissipative Axial Inflation
We analyze in detail the background cosmological evolution of a scalar field
coupled to a massless abelian gauge field through an axial term
, such as in the case of an axion. Gauge
fields in this case are known to experience tachyonic growth and therefore can
backreact on the background as an effective dissipation into radiation energy
density , which which can lead to inflation without the need of a flat
potential. We analyze the system, for momenta smaller than the cutoff
, including numerically the backreaction. We consider the evolution
from a given static initial condition and explicitly show that, if
is smaller than the field excursion by about a factor of at least
, there is a friction effect which turns on before that the
field can fall down and which can then lead to a very long stage of inflation
with a generic potential. In addition we find superimposed oscillations, which
would get imprinted on any kind of perturbations, scalars and tensors. Such
oscillations have a period of 4-5 efolds and an amplitude which is typically
less than a few percent and decreases linearly with . We also stress
that the comoving curvature perturbation on uniform density should be sensitive
to slow-roll parameters related to rather than ,
although we postpone a calculation of the power spectrum and of non-gaussianity
to future work and we simply define and compute suitable slow roll parameters.
Finally we stress that this scenario may be realized in the axion case, if the
coupling to U(1) (photons) is much larger than the coupling
to non-abelian gauge fields (gluons), since the latter sets the range
of the potential and therefore the maximal allowed .Comment: 22 pages, 27 figure
On the proper kinetic quadrupole CMB removal and the quadrupole anomalies
It has been pointed out recently that the quadrupole-octopole alignment in
the CMB data is significantly affected by the so-called kinetic Doppler
quadrupole (DQ), which is the temperature quadrupole induced by our proper
motion. Assuming our velocity is the dominant contribution to the CMB dipole we
have v/c = beta = (1.231 +/- 0.003) * 10^{-3}, which leads to a non-negligible
DQ of order beta^2. Here we stress that one should properly take into account
that CMB data are usually not presented in true thermodynamic temperature,
which induces a frequency dependent boost correction. The DQ must therefore be
multiplied by a frequency-averaged factor, which we explicitly compute for
several CMB maps finding that it varies between 1.67 and 2.47. This is often
neglected in the literature and turns out to cause a small but non-negligible
difference in the significance levels of some quadrupole-related statistics.
For instance the alignment significance in the SMICA 2013 map goes from
2.3sigma to 3.3sigma, with the frequency dependent DQ, instead of 2.9sigma
ignoring the frequency dependence in the DQ. Moreover as a result of a proper
DQ removal, the agreement across different map-making techniques is improved.Comment: v2: improvements to the text; 2 figures and several references added;
results unchanged. [14 pages, 3 tables, 2 figures
On systematic and GR effects on muon experiments
We derive in full generality the equations that govern the time dependence of
the energy of the decay electrons in a muon experiment. We
include both electromagnetic and gravitational effects and we estimate possible
systematics on the measurements of , whose experimental
uncertainty will soon reach . In addition to the
standard modulation of when the motion is orthogonal to a
constant magnetic field , with angular frequency , we
study effects due to: (1) a non constant muon factor, in presence of
electric fields , (2) a correction due to a component of the muon velocity
along (the `pitch correction'), (3) corrections to the precession rate due
to fields, (4) non-trivial spacetime metrics. Oscillations along the radial
and vertical directions of the muon lead to oscillations in with
a relative size of order , for the BNL experiment. We then find
a subleading effect in the `pitch' correction, leading to a frequency shift of
and subleading effects of
about due to fields. Finally we show that GR effects are
dominated by the Coriolis force, due to the Earth rotation with angular
frequency , leading to a correction of about . A similar correction might be more appreciable for future
electron experiments, being of order ,
compared to the present experimental uncertainty, , and forecasted to reach soon .Comment: 37 pages, 6 figure
The Higgs mass range from Standard Model false vacuum Inflation in scalar-tensor gravity
If the Standard Model is valid up to very high energies it is known that the
Higgs potential can develop a local minimum at field values around
GeV, for a narrow band of values of the top quark and Higgs
masses. We show that in a scalar-tensor theory of gravity such Higgs false
vacuum can give rise to viable inflation if the potential barrier is very
shallow, allowing for tunneling and relaxation into the electroweak scale true
vacuum. The amplitude of cosmological density perturbations from inflation is
directly linked to the value of the Higgs potential at the false minimum.
Requiring the top quark mass, the amplitude and spectral index of density
perturbations to be compatible with observations, selects a narrow range of
values for the Higgs mass, GeV, where the error is mostly
due to the theoretical uncertainty of the 2-loop RGE. This prediction could be
soon tested at the Large Hadron Collider. Our inflationary scenario could also
be further checked by better constraining the spectral index and the
tensor-to-scalar ratio.Comment: v1: 14 pages, 4 figures; v2: 18 pages, 8 figures, text improved, new
section and figures adde
Higgs mass and gravity waves in standard model false vacuum inflation
In previous publications we have proposed that inflation can be realized in a second minimum of the standard model Higgs potential at energy scales of about 1 0 16 GeV , if the minimum is not too deep and if a mechanism which allows a transition to the radiation dominated era can be found. This is provided, e.g., by scalar-tensor gravity models or hybrid models. Using such ideas we had predicted the Higgs boson mass to be of about 126 ± 3 GeV , which has been confirmed by the LHC, and that a possibly measurable amount of gravity waves should be produced. Using more refined recent theoretical calculations of the renormalization group equations we show that such scenario has the right scale of inflation only for small Higgs mass, lower than about 124 GeV, otherwise gravity waves are overproduced. The precise value is subject to some theoretical error and to experimental errors on the determination of the strong coupling constant. Finally we show that introducing a moderately large nonminimal coupling for the Higgs field the bound can shift to larger values and be reconciled with the LHC measurements of the Higgs mass
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