Damping parametric instabilities in future gravitational wave detectors by means of electrostatic actuators

Posted by klaurent MIT

Kavli Affiliate: Richard Mittleman | Summary:It has been suggested that the next generation of interferometric gravitational wave detectors may observe spontaneously excited parametric oscillatory instabilities. We present a method of actively suppressing any such instability through application of electrostatic forces to the interferometers’ test masses. Using numerical methods we quantify the actuation force required to […]


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Core or cusps: The central dark matter profile of a redshift one strong lensing cluster with a bright central image

Posted by klaurent Stanford

Kavli Affiliate: Rafe Schindler | Summary:We report on SPT-CLJ2011-5228, a giant system of arcs created by a cluster at $z=1.06$. The arc system is notable for the presence of a bright central image. The source is a Lyman Break galaxy at $z_s=2.39$ and the mass enclosed within the 14 arc second radius Einstein ring is […]


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Equivalent Model of Transient Gyrotron Cathode Response

Posted by klaurent Peking

Kavli Affiliate: Fukun Liu| Summary: The gyrotron is the high power millimeter wave source in the electron cyclotron resonance heating system for the tokamak. The cathode power supply is one of the most important ancillary devices for gyrotron. Some interesting transient phenomena about the cathode voltage and the cathode current was found in the gyrotron […]


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First Data Release of the Hyper Suprime-Cam Subaru Strategic Program

Posted by klaurent Tokyo

Kavli Affiliate: Hiroaki Aihara | Summary:The Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) is a three-layered imaging survey aimed at addressing some of the most outstanding questions in astronomy today, including the nature of dark matter and dark energy. The survey has been awarded 300 nights of observing time at the Subaru Telescope and it started […]


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Two- and Three-Dimensional Probes of Parity in Primordial Gravity Waves

Posted by klaurent MIT

Kavli Affiliate: Kiyoshi Wesley Masui | Summary:We show that three-dimensional information is critical to discerning the effects of parity violation in the primordial gravity-wave background. If present, helical gravity waves induce parity-violating correlations in the cosmic microwave background (CMB) between parity-odd polarization $B$-modes and parity-even temperature anisotropies ($T$) or polarization $E$-modes. Unfortunately, $EB$ correlations are […]


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Canonical tilting relative generators

Posted by klaurent Tokyo

Kavli Affiliate: Alexey Bondal | Summary:Given a relatively projective birational morphism $fcolon Xto Y$ of smooth algebraic spaces with dimension of fibers bounded by 1, we construct tilting relative (over $Y$) generators $T_X,f$ and $S_X,f$ in $mathcalD^b(X)$. We develop a piece of general theory of strict admissible lattice filtrations in triangulated categories and show that […]


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An automated system to measure the quantum efficiency of CCDs for astronomy

Posted by klaurent Stanford

Kavli Affiliate: Homer Neal | Summary:We describe a system to measure the Quantum Efficiency in the wavelength range of 300 nm to 1100 nm of 40×40 mm n-channel CCD sensors for the construction of the 3.2 gigapixel LSST focal plane. The technique uses a series of instrument to create a very uniform flux of photons […]


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ALMA Long Baseline Campaigns: Phase Characteristics of Atmosphere at Long Baselines in the Millimeter and Submillimeter Wavelengths

Posted by klaurent Cambridge

Kavli Affiliate: Richard Hills | Summary:This paper presents the first detailed investigation of the characteristics of mm/submm phase fluctuation and phase correction methods obtained using ALMA with baseline lengths up to ~15 km. Most of the spatial structure functions (SSFs) show that the phase fluctuation increases as a function of baseline length, with a power-law […]


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Multigraded linear series and recollement

Posted by klaurent Tokyo

Kavli Affiliate: Yukari Ito | Summary:Given a scheme $Y$ equipped with a collection of globally generated vector bundles $E_1, dots, E_n$, we study the universal morphism from $Y$ to a fine moduli space $mathcalM(E)$ of cyclic modules over the endomorphism algebra of $E:=mathcalO_Yoplus E_1opluscdots oplus E_n$. This generalises the classical morphism to the linear series […]


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Massively Parallel Computation of Accurate Densities for N-body Dark Matter Simulations using the Phase-Space-Element Method

Posted by klaurent Stanford

Kavli Affiliate: Ralf Kaehler | Summary:This paper presents an accurate density computation approach for large dark matter simulations, based on a recently introduced phase-space tessellation technique and designed for massively parallel, heterogeneous cluster architectures. We discuss a memory efficient construction of an oct-tree structure to sample the mass densities with locally adaptive resolution, according to […]


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