5,354 research outputs found
Spin induced multipole moments for the gravitational wave amplitude from binary inspirals to 2.5 Post-Newtonian order
Using the NRGR effective field theory formalism we calculate the remaining
source multipole moments necessary to obtain the spin contributions to the
gravitational wave amplitude to 2.5 Post-Newtonian (PN) order. We also
reproduce the tail contribution to the waveform linear in spin at 2.5PN arising
from the nonlinear interaction between the current quadrupole and the mass
monopole.Comment: 17 pages, 4 figures. v2 Minor changes, to appear in JCA
Fermion masses in a model for spontaneous parity breaking
In this paper we discuss a left-right symmetric model for elementary
particles and their connection with the mass spectrum of elementary fermions.
The model is based on the group . New
mirror fermions and a minimal set of Higgs particles that breaks the symmetry
down to are proposed. The model can accommodate a consistent
pattern for charged and neutral fermion masses as well as neutrino
oscillations. An important consequence of the model is that the connection
between the left and right sectors can be done by the neutral vector gauge
bosons Z and a new heavy Z'.Comment: 7 pages, 3 figures. Accepted in Eur. Phys. J.
Interaction-induced excited-band condensate in a double-well optical lattice
We show theoretically that interaction effects in a double-well optical
lattice can induce condensates in an excited band. For a symmetric double-well
lattice, bosons condense into the bottom of the excited band at the edge of the
Brillouin Zone if the chemical potential is above a critical value. For an
asymmetric lattice, a condensate with zero momentum is automatically induced in
the excited band by the condensate in the lowest band. This is due to a
combined effect of interaction and lattice potential, which reduces the band
gap and breaks the inversion symmetry. Our work can be generalized to a
superlattice composed of multiple-well potentials at each lattice site, where
condensates can be induced in even higher bands.Comment: 4pages, 3 figure
Constraints on a scale-dependent bias from galaxy clustering
We forecast the future constraints on scale-dependent parametrizations of
galaxy bias and their impact on the estimate of cosmological parameters from
the power spectrum of galaxies measured in a spectroscopic redshift survey. For
the latter we assume a wide survey at relatively large redshifts, similar to
the planned Euclid survey, as baseline for future experiments. To assess the
impact of the bias we perform a Fisher matrix analysis and we adopt two
different parametrizations of scale-dependent bias. The fiducial models for
galaxy bias are calibrated using a mock catalogs of H emitting galaxies
mimicking the expected properties of the objects that will be targeted by the
Euclid survey.
In our analysis we have obtained two main results. First of all, allowing for
a scale-dependent bias does not significantly increase the errors on the other
cosmological parameters apart from the rms amplitude of density fluctuations,
, and the growth index , whose uncertainties increase by a
factor up to two, depending on the bias model adopted. Second, we find that the
accuracy in the linear bias parameter can be estimated to within 1-2\%
at various redshifts regardless of the fiducial model. The non-linear bias
parameters have significantly large errors that depend on the model adopted.
Despite of this, in the more realistic scenarios departures from the simple
linear bias prescription can be detected with a significance at
each redshift explored.
Finally, we use the Fisher Matrix formalism to assess the impact of assuming
an incorrect bias model and found that the systematic errors induced on the
cosmological parameters are similar or even larger than the statistical ones.Comment: new section added; conclusions unchanged; accepted for publication in
PR
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