694 research outputs found
Magnification effect on the detection of primordial non-Gaussianity from photometric surveys
We present forecast results for constraining the primordial non-Gaussianity
from photometric surveys through a large-scale enhancement of the galaxy
clustering amplitude. In photometric surveys, the distribution of observed
galaxies at high redshifts suffers from the gravitational-lensing
magnification, which systematically alters the number density for
magnitude-limited galaxy samples. We estimate size of the systematic bias in
the best-fit cosmological parameters caused by the magnification effect,
particularly focusing on the primordial non-Gaussianity. For upcoming deep
and/or wide photometric surveys like HSC, DES and LSST, the best-fit value of
the non-Gaussian parameter, fNL, obtained from the galaxy count data is highly
biased, and the true values of fNL would typically go outside the 3-sigma error
of the biased confidence region, if we ignore the magnification effect in the
theoretical template of angular power spectrum. The additional information from
cosmic shear data helps not only to improve the constraint, but also to reduce
the systematic bias. As a result, the size of systematic bias on fNL would
become small enough compared to the expected 1-sigma error for HSC and DES, but
it would be still serious for deep surveys with z_m > 1.5, like LSST.
Tomographic technique improves the constraint on fNL by a factor of 2-3
compared to the one without tomography, but the systematic bias would increase.Comment: 12 pages, 10 figure
Morphology of Weak Lensing Convergence Maps
We study the morphology of convergence maps by perturbatively reconstructing their Minkowski Functionals (MFs). We present a systematics study using a set of three generalised skew-spectra as a function of source redshift and smoothing angular scale. Using an approach based on pseudo-s (PSL) we show how these spectra will allow reconstruction of MFs in the presence of an arbitrary mask and inhomogeneous noise in an unbiased way. Our theoretical predictions are based on a recently introduced fitting function to the bispectrum. We compare our results against state-of-the art numerical simulations and find an excellent agreement. The reconstruction can be carried out in a controlled manner as a function of angular harmonics and source redshift which allows for a greater handle on any possible sources of non-Gaussianity. Our method has the advantage of estimating the topology of convergence maps directly using shear data. We also study weak lensing convergence maps inferred from Cosmic Microwave Background (CMB) observations; and we find that, though less significant at low redshift, the post-Born corrections play an important role in any modelling of the non-Gaussianity of convergence maps at higher redshift. We also study the cross-correlations of estimates from different tomographic bins
Fibrations of genus two on complex surfaces
We consider fibrations of genus 2 over complex surfaces. The purpose of this
paper is primarily to provide a geometric description of the possible
structures of the fibration on a neighborhood of a singular fiber. In
particular it is shown that the "geometric data" of the singular fiber
determines the fibration on its neighborhood up to a transversely holomorphic
-diffeomorphism. The method employed is quite flexible and it
applies to good extent to fibrations of arbitrary genus.Comment: This is the final version, June 201
Position-Dependent Correlation Function of Weak Lensing Convergence
We provide a systematic study of the position-dependent correlation function
in weak lensing convergence maps and its relation to the squeezed limit of the
three-point correlation function (3PCF) using state-of-the-art numerical
simulations. We relate the position-dependent correlation function to its
harmonic counterpart, i.e., the position-dependent power spectrum or
equivalently the integrated bispectrum. We use a recently proposed improved
fitting function, BiHalofit, for the bispectrum to compute the theoretical
predictions as a function of source redshifts. In addition to low redshift
results () we also provide results for maps inferred from lensing
of the cosmic microwave background, i.e., . We include a {\em
Euclid}-type realistic survey mask and noise. In agreement with the recent
studies on the position-dependent power spectrum, we find that the results from
simulations are consistent with the theoretical expectations when appropriate
corrections are included.Comment: 7 pages, 7 figure
Poisson-de Rham homology of hypertoric varieties and nilpotent cones
We prove a conjecture of Etingof and the second author for hypertoric
varieties, that the Poisson-de Rham homology of a unimodular hypertoric cone is
isomorphic to the de Rham cohomology of its hypertoric resolution. More
generally, we prove that this conjecture holds for an arbitrary conical variety
admitting a symplectic resolution if and only if it holds in degree zero for
all normal slices to symplectic leaves.
The Poisson-de Rham homology of a Poisson cone inherits a second grading. In
the hypertoric case, we compute the resulting 2-variable Poisson-de
Rham-Poincare polynomial, and prove that it is equal to a specialization of an
enrichment of the Tutte polynomial of a matroid that was introduced by Denham.
We also compute this polynomial for S3-varieties of type A in terms of Kostka
polynomials, modulo a previous conjecture of the first author, and we give a
conjectural answer for nilpotent cones in arbitrary type, which we prove in
rank less than or equal to 2.Comment: 25 page
Knot homology via derived categories of coherent sheaves II, sl(m) case
Using derived categories of equivariant coherent sheaves we construct a knot
homology theory which categorifies the quantum sl(m) knot polynomial. Our knot
homology naturally satisfies the categorified MOY relations and is
conjecturally isomorphic to Khovanov-Rozansky homology. Our construction is
motivated by the geometric Satake correspondence and is related to Manolescu's
by homological mirror symmetry.Comment: 51 pages, 9 figure
DNA Sexing of the Philippine Eagle (Pithecophaga jefferyi Ogilvie-Grant) in Captivity at the Philippine Eagle Center, Davao City, Philippines
The Philippine eagle is a sexually monomorphic raptor which lacks the sex-linked morphology determining the gender especially in the juveniles. Thus, a PCR amplification technique was used to determine the sex of 24 eagles at different stages of development (2 to 37 years old) in captivity at the Philippine Eagle Center, Malagos Davao City. Fractions of the sex-linked genes, CHD-W and CHD-Z of each individual were amplified. Ka Brianne (female) and Jag (male) having 9 offspring conceived through artificial insemination were used as positive controls for sex identification of 22 other individuals. Two individuals of Gallus domesticus with confirmed genders were also included and run through PCR amplification together with the Philippine eagles using primers CHDFORNEW and CHDREVNEW to test the method. Females revealed two distinct bands (290 bp and 280 bp in size) while the males revealed only a single band of 280 bp. Eleven eagles were found to be females while 13 were found to be males. DNA sexing gave a 100% confirmation of the assigned sexes of the eagles, which were obtained through morphometric analysis done by personnel at the captive breeding center. DNA sexing could be a practical technique in sexing newly hatched eaglet and juveniles, naming of eagles, establishing life history characteristics, and pairing attempt or assignment of partners in the threatened avian species such as the Philippine eagles
Neutrino masses, cosmological bound and four zero Yukawa textures
Four zero neutrino Yukawa textures in a specified weak basis, combined with
symmetry and type-I seesaw, yield a highly constrained and predictive
scheme. Two alternately viable light neutrino Majorana mass matrices
result with inverted/normal mass ordering. Neutrino
masses, Majorana in character and predicted within definite ranges with
laboratory and cosmological inputs, will have their sum probed cosmologically.
The rate for decay, though generally below the reach of
planned experiments, could approach it in some parameter region. Departure from
symmetry due to RG evolution from a high scale and consequent CP
violation, with a Jarlskog invariant whose magnitude could almost reach
, are explored.Comment: Published versio
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