2,128 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
On the Gorenstein locus of some punctual Hilbert schemes
Let be an algebraically closed field and let \Hilb_{d}^{G}(\p{N}) be
the open locus of the Hilbert scheme \Hilb_{d}(\p{N}) corresponding to
Gorenstein subschemes. We prove that \Hilb_{d}^{G}(\p{N}) is irreducible for
, we characterize geometrically its singularities for and we
give some results about them when which give some evidence to a
conjecture on the nature of the singular points in \Hilb_{d}^{G}(\p{N}).Comment: The exposition has been improved and some of the main results have
been extended to degree $d\le 9
A structure theorem for 2-stretched Gorenstein algebras
In this paper we study the isomorphism classes of local, Artinian, Gorenstein
k-algebras A whose maximal ideal M satisfies dim_k(M^3/M^4)=1 by means of
Macaulay's inverse system generalizing a recent result by J. Elias and M.E.
Rossi. Then we use such results in order to complete the description of the
singular locus of the Gorenstein locus of the punctual Hilbert scheme of degree
11.Comment: 24 pages. We removed lemma 2.1 because it was false and we modified
the proof of proposition 3.2 accordingly inserting some new due reference
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
Examples of rank two aCM bundles on smooth quartic surfaces in
Let be a smooth quartic surface and let
. In the
present paper we classify locally free sheaves of rank on
such that , and
for . We also deal with
their stability.Comment: 22 pages. Exposition improve
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
TDOA--based localization in two dimensions: the bifurcation curve
In this paper, we complete the study of the geometry of the TDOA map that
encodes the noiseless model for the localization of a source from the range
differences between three receivers in a plane, by computing the Cartesian
equation of the bifurcation curve in terms of the positions of the receivers.
From that equation, we can compute its real asymptotic lines. The present
manuscript completes the analysis of [Inverse Problems, Vol. 30, Number 3,
Pages 035004]. Our result is useful to check if a source belongs or is closed
to the bifurcation curve, where the localization in a noisy scenario is
ambiguous.Comment: 11 pages, 3 figures, to appear in Fundamenta Informatica
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