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Relic neutrinos: Physically consistent treatment of effective number of neutrinos and neutrino mass

Physical Review D 2014年第2期89卷 023008-023008页

作者： Jeremiah Birrell Cheng-Tao Yang Pisin Chen Johann Rafelski Program in Applied Mathematics The University of Arizona Tucson Arizona 85721 USA Department of Physics and Graduate Institute of Astrophysics National Taiwan University Taipei Taiwan 10617 Leung Center for Cosmology and Particle Astrophysics (LeCosPA) National Taiwan University Taipei Taiwan 10617 Kavli Institute for Particle Astrophysics and Cosmology SLAC National Accelerator Laboratory Menlo Park California 94025 USA Department of Physics The University of Arizona Tucson Arizona 85721 USA

We perform a model independent study of the neutrino momentum distribution at freeze-out, treating the freeze-out temperature as a free parameter. Our results imply that measurement of neutrino reheating, as characterized by the measurement of the effective number of neutrinos Nν, amounts to the determination of the neutrino kinetic freeze-out temperature within the context of the standard model of particle physics where the number of neutrino flavors is fixed and no other massless (fractional) particles arise. At temperatures on the order of the neutrino mass, we show how cosmic background neutrino properties, i.e., energy density, pressure, and particle density, are modified in a physically consistent way as a function of neutrino mass and Nν.

关键词： Relic mass neutrinos neutrino mass Momentum distribution Particle physics Neutrinos standard model (particle physics)

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Erratum: Glassy Chimeras could be blind to quantum speedup: Designing better benchmarks for quantum annealing machines [Phys. Rev. X 4, 021008 (2014)]

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Physical Review X 2015年第1期5卷 019901-019901页

作者： Martin Weigel Helmut G. Katzgraber Jonathan Machta Firas Hamze Ruben S. Andrist Applied Mathematics Research Centre Coventry University Coventry CV1 5FB United Kingdom Department of Physics and Astronomy Texas A&M University College Station Texas 77843-4242 USA Materials Science and Engineering Program Texas A&M University College Station Texas 77843 USA Santa Fe Institute 1399 Hyde Park Road Santa Fe New Mexico 87501 USA Physics Department University of Massachusetts Amherst Massachusetts 01003 USA D-Wave Systems Inc. 3033 Beta Avenue Burnaby British Columbia V5G 4M9 Canada

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Flexible Metallic Nanowires with Self-Adaptive Contacts to Semiconducting Transition-Metal Dichalcogenide Monolayers

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Microscopy and Microanalysis 2014年第S3期20卷 1760-1761页

作者： Junhao Lin Ovidiu Cretu Wu Zhou Kazu Suenaga Dhiraj Prasai Kirill I. Bolotin Nguyen Thanh Cuong Minoru Otani Susumu Okada Andrew R. Lupini Department of Physics and Astronomy Vanderbilt University Nashville TN 37235 USA Materials Science & Technology Division Oak Ridge National Laboratory Oak Ridge TN 37831 USA National Institute of Advanced Industrial Science and Technology (AIST) Tsukuba 305-8565 Japan Interdisciplinary Graduate Program in Materials Science Vanderbilt University Nashville TN 37235 USA Graduate School of Pure and Applied Sciences University of Tsukuba Tsukuba 305-8571 Japan

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MICRO-OPTOFLUIDIC RING RESONATOR STRUCTURES FOR SELECTIVE DETECTION OF ORGANIC VAPORS

MICRO-OPTOFLUIDIC RING RESONATOR STRUCTURES FOR SELECTIVE DE...

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International Conference on Solid-State Sensors, Actuators and Microsystems

作者： K. Scholten K. Reddy X. Fan E.T. Zellers Applied Physics Program University of Michigan Department of Biomedical Engineering University of Michigan

ISBN: (纸本)9781467359825

A microfabricated optofluidic ring resonator (μOFRR) sensor for volatile organic compounds (VOC) is described. SiO_x optical resonators integrated into a microfluidic pathway were defined lithographically and fabricated via Si micromachining. Whispering gallery mode resonances with quality factors exceeding 10~4 were excited in devices with diameters of 50-250 μm and wall thicknesses of 1.5-2 μm. Fluidic interconnections and structures for alignment of optical fiber waveguides were integrated into the larger μOFRRs. Devices coated internally with a thin PDMS layer exhibit shifts in resonant wavelengths during VOC exposure with sub-ng detection limits. In related work, selective VOC measurements obtained with plasmonic films of functionalized nanoparticles are described, with a goal of using them in place of polymer coatings in the μOFRR. A thin film of octanethiolate monolayer protected gold nanoparticles (MPN) was coated on a planar substrate and capped with a microfluidic cell. Reflected light from one of two single wavelength sources (783 nm and 488 nm) was measured during separate dynamic exposures to two VOCs. The decrease in reflected light intensity, due to film selling and changes in the local surface plasmon resonance band, was proportional to the VOC concentration. The ratio of responses at each wavelength provided a pattern unique to each VOC.

关键词： Sensor Vapor Optical Optofluidic Nanoparticle

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Compact Ultradense Matter Impactors

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Physical Review Letters 2013年第11期110卷 111102-111102页

作者： Johann Rafelski Lance Labun Jeremiah Birrell Department of Physics The University of Arizona Tucson Arizona 85721 USA Program in Applied Mathematics The University of Arizona Tucson Arizona 85721 USA

We study interactions of meteorlike compact ultradense objects (CUDO), having nuclear or greater density, with Earth and other rocky bodies in the Solar System as a possible source of information about novel forms of matter. We study the energy loss in CUDO puncture of the body and discuss differences between regular matter and CUDO impacts.

关键词： CASCADE impactors (Meteorological instruments) RESEARCH SOLAR system NUCLEAR density ENERGY dissipation MATTER

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DESIGN OF DECISION DEVICE FOR THE ADAPTATION OF DECISION DIRECTED EQUALIZERS

DESIGN OF DECISION DEVICE FOR THE ADAPTATION OF DECISION DIR...

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IEEE International Conference on Acoustics, Speech, and Signal Processing

作者： Atulya Yellepeddi James C. Preisig Electrical Eng./Applied Ocean Physics and Eng. MIT-WHOI Joint Program Applied Ocean Physics and Engineering Woods Hole Oceanographic Institution

ISBN: (纸本)9781479903573

Adaptation of the coefficients of an equalizer usually takes place in the decision directed mode. The decision used for adaptation has a profound influence on the performance of the equalizer. In this work, we consider the influence of the probabilistic model used by a soft information decision device on the performance of the equalizer. It is shown that the equalizer output is distributed as a Gaussian Mixture, and these statistics are used to form a soft-decision device. We show that this is very near optimal in the sense of the Recursive Expected Least Squares algorithm introduced in prior work. Sub-optimal decision devices that are often more practical are also introduced and the loss of performance as a result of using these is considered.

关键词： Equalizers adaptive signal processing adaptive equalizers time-varying channels

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Nonlocal correlations in a proximity-coupled normal-metal

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Physical Review B 2013年第2期88卷 024502-024502页

作者： Taewan Noh Sam Davis Venkat Chandrasekhar Department of Physics and Astronomy Northwestern University Evanston Illinois 60208 USA Graduate Program in Applied Physics Northwestern University Evanston Illinois 60208 USA

We report evidence of large, nonlocal correlations between two spatially separated normal-metals in superconductor/normal-metal (SN) heterostructures, which manifest themselves as nonlocal voltage generated in response to a driving current. Unlike prior experiments in SN heterostructures, the nonlocal correlations are mediated not by a superconductor, but by a proximity-coupled normal-metal. The nonlocal correlations extend over relatively long length scales in comparison to the superconducting case. At very low temperatures, we find a reduction in the nonlocal voltage for small applied currents that cannot be explained by the quasiclassical theory of superconductivity, which we believe is a signature of new long-range quantum correlations in the system.

关键词： HETEROSTRUCTURES SUPERCONDUCTORS NONMETALS SUPERCONDUCTIVITY QUANTUM correlations LOW temperatures QUASI-classical trajectory method

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Avian photoreceptor patterns represent a disordered hyperuniform solution to a multiscale packing problem

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Physical Review E 2014年第2期89卷 022721-022721页

作者： Yang Jiao Timothy Lau Haralampos Hatzikirou Michael Meyer-Hermann Joseph C. Corbo Salvatore Torquato Princeton Institute of the Science and Technology of Materials Princeton University Princeton New Jersey 08540 USA Materials Science and Engineering Arizona State University Tempe Arizona 85287 USA Department of Pathology and Immunology Washington University School of Medicine St. Louis Missouri 63110 USA Department of Systems Immunology Helmholtz Centre for Infection Research Braunschweig Germany Center for Advancing Electronics Dresden TU Dresden 01062 Dresden Germany Department of Chemistry Department of Physics Program in Computational and Applied Mathematics Princeton University Princeton New Jersey 08544 USA

Optimal spatial sampling of light rigorously requires that identical photoreceptors be arranged in perfectly regular arrays in two dimensions. Examples of such perfect arrays in nature include the compound eyes of insects and the nearly crystalline photoreceptor patterns of some fish and reptiles. Birds are highly visual animals with five different cone photoreceptor subtypes, yet their photoreceptor patterns are not perfectly regular. By analyzing the chicken cone photoreceptor system consisting of five different cell types using a variety of sensitive microstructural descriptors, we find that the disordered photoreceptor patterns are “hyperuniform” (exhibiting vanishing infinite-wavelength density fluctuations), a property that had heretofore been identified in a unique subset of physical systems, but had never been observed in any living organism. Remarkably, the patterns of both the total population and the individual cell types are simultaneously hyperuniform. We term such patterns “multihyperuniform” because multiple distinct subsets of the overall point pattern are themselves hyperuniform. We have devised a unique multiscale cell packing model in two dimensions that suggests that photoreceptor types interact with both short- and long-ranged repulsive forces and that the resultant competition between the types gives rise to the aforementioned singular spatial features characterizing the system, including multihyperuniformity. These findings suggest that a disordered hyperuniform pattern may represent the most uniform sampling arrangement attainable in the avian system, given intrinsic packing constraints within the photoreceptor epithelium. In addition, they show how fundamental physical constraints can change the course of a biological optimization process. Our results suggest that multihyperuniform disordered structures have implications for the design of materials with novel physical properties and therefore may represent a fruitful area for future research

关键词： PHOTORECEPTORS ARRAY processing BIRDS MULTISCALE modeling SAMPLING (Signal processing) EPITHELIUM

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A Questionnaire on Materialisms

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OCTOBER 2016年第155期 3-110页

作者： [Anonymous] EMILY APTER is Chair of the Department of Comparative Literature at NYU and coeditor of the Dictionary of Untranslatables: A Philosophical Lexicon (Princeton 2014). ED ATKINS is an artist who lives in Berlin. ARMEN AVANESSIAN is a philosopher and the editor-in-chief at Merve Verlag Berlin founder of . BILL BROWN author of “Thing Theory” (Critical Inquiry 28 Autumn 2001) and Other Things (Chicago 2015) teaches at the University of Chicago. GIULIANA BRUNO is Emmet Blakeney Gleason Professor of Visual and Environmental Studies at Harvard University. JULIA Bryan-Wilson is Associate Professor of Contemporary Art at UC Berkeley. D. GRAHAM BURNETT writes and makes things. He teaches at Princeton and is an editor at Cabinet. MEL Y. CHEN is Associate Professor of Gender and Women's Studies at UC Berkeley and the author of Animacies (Duke 2012). ANDREW COLE is professor of English and director of the Gauss Seminars at Princeton University. His most recent book is The Birth of Theory (Chicago 2014). CHRISTOPH COX is Professor of Philosophy at Hampshire College. SUHAIL MALIK is co-director of MFA Fine Art Goldsmiths London and author of On the Necessity of Art's Exit from Contemporary Art (Urbanomic 2016). T. J. DEMOS is Professor in the Department of the History of Art and Visual Culture University of California Santa Cruz and Director of its Center for Creative Ecologies. JEFF DOLVEN teaches English at Princeton University and is an editor-at-large at Cabinet magazine. DAVID T. DORIS is Associate Professor at the University of Michigan directly above the center of the Earth. He wrote Vigilant Things (Washington 2011). HELMUT DRAXLER is professor for Art Theory at the University of Applied Arts in Vienna. PATRICIA FALGUIÈRES is a professor at the École des Hautes Études en Sciences Sociales (EHESS) Paris. PETER GALISON is the Joseph Pellegrino University Professor in History of Science and Physics at Harvard University. ALEXANDER R. GALLOWAY teaches media theory at New York University. RACHEL HAIDU is Asso

Recent philosophical tendencies of Actor-Network Theory, Object-Oriented Ontology, and Speculative Realism have profoundly challenged the centrality of subjectivity in the humanities, and many artists and curators, particularly in the UK, Germany, and the United States, appear deeply influenced by this shift from epistemology to ontology. October editors asked artists, historians, and philosophers invested in these projectsfrom Graham Harman and Alexander R. Galloway to Armen Avanessian and Patricia Falguieres to Ed Atkins and Amie Siegelto explore what the rewards and risks of assigning agency to objects may be, and how, or if, such new materialisms can be productive for making and thinking about art today.

关键词： Objectivity in art Materialism Art & society

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Coronary CT angiography:State of the art

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World Journal of Cardiology 2013年第12期5卷 453-458页

作者： Akmal Sabarudin Zhonghua Sun Diagnostic Imaging and Radiotherapy Program School of Diagnostic and Applied Health SciencesFaculty of Health SciencesUniversity Kebangsaan Malaysia Discipline of Medical Imaging Department of Imaging and Applied PhysicsCurtin University

The aim o this article is to discuss the protocol o betablockers that is commonly used or prospectively ECGtriggered coronary computed tomography angiography(CCTA).It is essential to ensure a low and regular heart rate in patients undergoing prospectively ECG-triggered CCTA or optimal visualization o coronary *** early generations o computed tomographyscanners are not applicable to be tailored according to patients’heart rate,a low and regular heart rate is possible to be achieved by the administration o medications according to the beta-blocker *** can be sa ely administered to reduce patients’heart rate or CCTA examination i patients are screened or certain contraindications.

关键词： Beta-blockers Coronary computed tomography angiography Heart rate Prospective ECG-triggering

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