118703594
Delensing Galaxy Surveys
Weak gravitational lensing can cause displacements, magnification, rotation and shearing of the images of distant galaxies. Most studies focus on the shear and magnification effects since they are more easily observed. In this paper we focus on the effect of lensing displacements on wide field images. Galaxies at redshifts 0.5--1 are typically displaced by 1 arcminute, and the displacements are coherent over degree-size patches. However the displacement effect is redshift-dependent, so there is a visible relative shift between galaxies at different redshifts, even if they are close on the sky. We show that the reconstruction of the original galaxy position is now feasible with lensing surveys that cover many hundreds of square degrees. We test with simulations two approaches to "delensing": one uses shear measurements and the other uses the foreground galaxy distribution as a proxy for the mass. We also estimate the effect of foreground deflections on galaxy-galaxy lensing measurements and find it is relevant only for LSST and Euclid-era surveys.
22489858
A multichamber system for analyzing the outgassing, deposition, and associated optical degradation properties of materials in a vacuum.
We report on the camera materials test chamber, a multivessel apparatus that analyzes the outgassing consequences of candidate materials for use in the vacuum cryostat of a new telescope camera. The system measures the outgassing products and rates of samples of materials at different temperatures and collects films of outgassing products to measure the effects on light transmission in six optical bands. The design of the apparatus minimizes potential measurement errors introduced by background contamination.
59269082
Higher spin gravity with matter in AdS3 and its CFT dual
A bstractWe study Vasiliev’s system of higher spin gauge fields coupled to massive scalars in AdS3, and compute the tree level two and three point functions. These are compared to the large N limit of the WN minimal model, and nontrivial agreements are found. We propose a modified version of the conjecture of Gaberdiel and Gopakumar, under which the bulk theory is perturbatively dual to a subsector of the CFT that closes on the sphere.
118696108
Non-Minimal Higher-Spin DS4/CFT3
We conjecture that the level k U(N) Chern-Simons theory coupled to free anticommuting scalar matter in the fundamental is dual to non-minmal higher-spin Vasiliev gravity in dS4 with parity-violating phase \theta0 = \pi N/2k and Neumann boundary conditions for the scalar. Related conjectures are made for fundamental commuting spinor matter and critical theories. This generalizes a recent conjecture relating the minimal Type A Vasiliev theory in dS4 to the Sp(N) model with fundamental real anti-commuting scalars.
118483093
Spectrum for heavy quarkonia and mixture of the relevant wave functions within the framework of Bethe-Salpeter equation
Considering the fact that some excited states of the heavy quarkonia (charmonium and bottomonium) are still missing in experimental observations and potential applications of the relevant wave functions of the bound states, we re-analyze the spectrum and the relevant wave functions of the heavy quarkonia within the framework of Bethe-Salpeter (B.S.) equation with a proper QCD-inspired kernel. Such a kernel for the heavy quarkonia, relating to potential of the non-relativistic quark model, is instantaneous, so we call the corresponding B.S. equation as BS-In equation throughout the paper. Particularly, a new way to solve the B.S. equation, which is different from the traditional ones, is proposed here, and with it not only the known spectrum for the heavy quarkonia is re-generated, but also an important issue is brought in, i.e., the obtained solutions of the equation ‘automatically’ include the ‘fine’, ‘hyperfine’ splittings and the wave function mixture, such as S-D wave mixing in JPC = 1−− states, P-F wave mixing in JPC = 2++ states for charmonium, bottomonium etc. It is pointed out that the best place to test the wave mixture probably is at Z-factory (e+e− collider running at Z-boson pole with extremely high luminosity).
27784575
Numerical Simulation of High Power Microwave Sources
Electromagnetic fully relativistic particle-in-cell codes are a powerful tool for modeling and designing components of high power microwave sources and accelerator systems. This paper reviews the principles and properties of numerical simulation codes as applied to problems of microwave generation. The important aspects which can be treated with such codes are, improved representation of microwave circuits in complicated geometries, proper treatment of nonlinear particle wave interaction in the body of a device, inclusion of self-consistent self-field effects, and treatment of surface properties such as emission, secondary particles, and surface breakdown. Examples of application of two- and three-dimensional codes to specific devices such as gyrotrons, magnetrons, and klystrons is presented. The information obtained from large numerical simulation codes provides both detailed insight hNto source physics as well as the basis for improved design technology.