3,943 research outputs found
Weak Lensing of Intensity Mapping: the Cosmic Infrared Background
Gravitational lensing deflects the paths of cosmic infrared background (CIB)
photons, leaving a measurable imprint on CIB maps. The resulting statistical
anisotropy can be used to reconstruct the matter distribution out to the
redshifts of CIB sources. To this end, we generalize the CMB lensing quadratic
estimator to any weakly non-Gaussian source field, by deriving the optimal
lensing weights. We point out the additional noise and bias caused by the
non-Gaussianity and the `self-lensing' of the source field. We propose methods
to reduce, subtract or model these non-Gaussianities. We show that CIB lensing
should be detectable with Planck data, and detectable at high significance for
future CMB experiments like CCAT-Prime. The CIB thus constitutes a new source
image for lensing studies, providing constraints on the amplitude of structure
at intermediate redshifts between galaxies and the CMB. CIB lensing
measurements will also give valuable information on the star formation history
in the universe, constraining CIB halo models beyond the CIB power spectrum. By
laying out a detailed treatment of lens reconstruction from a weakly
non-Gaussian source field, this work constitutes a stepping stone towards lens
reconstruction from continuum or line intensity mapping data, such as the
Lyman-alpha emission, absorption, and the 21cm radiation.Comment: Accepted in Physical Review
Finite frequency noise for edge states at filling factor
We investigate the properties of the finite frequency noise in a quantum
point contact geometry for the fractional quantum Hall state at filling factor
. The results are obtained in the framework of the Wen's hierarchical
model.
We show that the peak structure of the colored noise allows to discriminate
among different possible excitations involved in the tunneling. In particular,
optimal values of voltage and temperature are found in order to enhance the
visibility of the peak associated with the tunneling of a 2-agglomerate, namely
an excitation with charge double of the fundamental one associated to the
single quasiparticle.Comment: 5 pages, 1 figure, to be published in the Proceedings of the
Conference on the Frontiers of Quantum and Mesoscopic Thermodynamics (FQMT11
The optical companion to the binary millisecond pulsar J1824-2452H in the globular cluster M28
We report on the optical identification of the companion star to the
eclipsing millisecond pulsar PSR J1824-2452H in the galactic globular cluster
M28 (NGC 6626). This star is at only 0.2" from the nominal position of the
pulsar and it shows optical variability (~ 0.25 mag) that nicely correlates
with the pulsar orbital period. It is located on the blue side of the cluster
main sequence, ~1.5 mag fainter than the turn-off point. The observed light
curve shows two distinct and asymmetric minima, suggesting that the companion
star is suffering tidal distortion from the pulsar. This discovery increases
the number of non-degenerate MSP companions optically identified so far in
globular clusters (4 out of 7), suggesting that these systems could be a common
outcome of the pulsar recycling process, at least in dense environments where
they can be originated by exchange interactions.Comment: accepted for publication on ApJ, 17 pages, 5 figure
Anomalous charge tunneling in the fractional quantum Hall edge states at filling factor \nu = 5/2
We explain effective charge anomalies recently observed for fractional
quantum Hall edge states at [M. Dolev, Y. Gross, Y. C. Chung, M.
Heiblum, V. Umansky, and D. Mahalu, Phys.Rev. B. \textbf{81}, 161303(R)
(2010)]. The experimental data of differential conductance and excess noise are
fitted, using the anti-Pfaffian model, by properly take into account
renormalizations of the Luttinger parameters induced by the coupling of the
system with an intrinsic noise. We demonstrate that a peculiar
agglomerate excitation with charge , double of the expected charge,
dominates the transport properties at low energies.Comment: 5 pages, 2 figure
Trigger :a musical theatre actor's guide to belting at gunpoint in the audition
In the world of Musical Theatre performance, auditioning is the first way for anyone to get a foot in the door. My thesis spends time figuring out a simple, helpful way in which actors can jump into their work within an audition setting through an audition trigger sheet that builds upon technique and tools that are easily accessible in an actor's armory. These 16 to 32 bars of music are what show directors and casting directors what an actor can do, and whether or not they are right for the part. Most of my time over the next few years will be spent auditioning for countless musicals. I will need a wide range of songs to choose from at a moment's notice, whether I am auditioning for a Golden Age Rogers + Hammerstein show or a contemporary Jason Robert Brown musical. This project includes a list of songs that I have in my book at every audition with all of the required analysis done. Each song has with it the trigger sheet that I have developed in order to activate a solid, compelling audition. The songs themselves each possess a specific internal audition cut. The trigger sheet I developed will be extremely helpful to me when I am at an audition, standing outside the door waiting for my time to enter. I can spend my time identifying with each of these songs and focusing on the story I want to tell. It will be an invaluable tool for me over the beginning years of my acting career.Thesis (B.?)Honors Colleg
Environmental induced renormalization effects in quantum Hall edge states
We propose a general mechanism for renormalization of the tunneling exponents
in edge states of the fractional quantum Hall effect. Mutual effects of the
coupling with out-of-equilibrium 1/f noise and dissipation are considered both
for the Laughlin sequence and for composite co- and counter-propagating edge
states with Abelian or non-Abelian statistics. For states with
counter-propagating modes we demonstrate the robustness of the proposed
mechanism in the so called disorder-dominated phase. Prototypes of these
states, such as \nu=2/3 and \nu=5/2, are discussed in detail and the rich
phenomenology induced by the presence of a noisy environment is presented. The
proposed mechanism justifies the strong renormalizations reported in many
experimental observations carried out at low temperatures. We show how
environmental effects could affect the relevance of the tunneling excitations,
leading to important implications in particular for the \nu=5/2 case.Comment: 14 pages, 4 figure
Charge tunneling in fractional edge channels
We explain recent experimental observations on effective charge of edge
states tunneling through a quantum point contact in the weak backscattering
regime. We focus on the behavior of the excess noise and on the effective
tunneling charge as a function of temperature and voltage. By introducing a
minimal hierarchical model different filling factors, \nu=p/(2p+1), in the Jain
sequence are treated on equal footing, in presence also of non-universal
interactions. The agreement found with the experiments for \nu=2/3 and \nu=2/5
reinforces the description of tunneling of bunching of quasiparticles at low
energies and quantitatively defines the condition under which one expects to
measure the fundamental quasiparticle charge. We propose high-order current
cumulant measurement to cross-check the validity of the above scenario and to
better clarify the peculiar temperature behavior of the effective charges
measured in the experiments.Comment: 6 pages, 3 figure
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