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arXiv 2020年

作者： Bolin, Bryce T. Fremling, Christoffer Holt, Timothy R. Hankins, Matthew J. Ahumada, Tomás Anand, Shreya Bhalerao, Varun Burdge, Kevin B. Copperwheat, Chris M. Coughlin, Michael Deshmukh, Kunal P. De, Kishalay Kasliwal, Mansi M. Morbidelli, Alessandro Purdum, Josiah N. Quimby, Robert Bodewits, Dennis Chang, Chan-Kao Ip, Wing-Huen Hsu, Chen-Yen Laher, Russ R. Lin, Zhong-Yi Lisse, Carey M. Masci, Frank J. Ngeow, Chow-Choong Tan, Hanjie Zhai, Chengxing Burruss, Rick Dekany, Richard Delacroix, Alexandre Duev, Dmitry A. Graham, Matthew Hale, David Kulkarni, Shrinivas R. Kupfer, Thomas Mahabal, Ashish Mróz, Przemyslaw J. Neill, James D. Riddle, Reed Rodriguez, Hector Smith, Roger M. Soumagnac, Maayane T. Walters, Richard Yan, Lin Zolkower, Jeffry Division of Physics Mathematics and Astronomy California Institute of Technology PasadenaCA91125 United States IPAC Mail Code 100-22 Caltech 1200 E. California Blvd. PasadenaCA91125 United States University of Southern Queensland Computational Engineering and Science Research Centre QLD Australia Southwest Research Institute Department of Space Studies BoulderCO80302 United States Department of Astronomy University of Maryland College ParkMD20742 United States Division of Physics Mathematics and Astronomy California Institute of Technology PasadenaCA91125 United States Department of Physics Indian Institute of Technology Bombay Powai Mumbai400076 India Astrophysics Research Institute Liverpool John Moores University 146 Brownlow Hill LiverpoolL3 5RF United Kingdom School of Physics and Astronomy University of Minnesota MinneapolisMN55455 United States Department of Metallurgical Engineering and Materials Science Indian Institute of Technology Bombay Powai Mumbai400076 India Université Côte d’Azur Observatoire de la Côte d’Azur CNRS Laboratoire Lagrange Boulevard de l’Observatoire CS 34229 Nice cedex 406304 France Department of Astronomy San Diego State University 5500 Campanile Dr San DiegoCA92182 United States University of Tokyo Institutes for Advanced Study University of Tokyo KashiwaChiba277-8583 Japan Physics Department Leach Science Center Auburn University AuburnAL36832 United States Institute of Astronomy National Central University 32001 Taiwan Johns Hopkins University Applied Physics Laboratory LaurelMD20723 United States Jet Propulsion Laboratory California Institute of Technology 4800 Oak Grove Drive PasadenaCA91109 United States Caltech Optical Observatories California Institute of Technology PasadenaCA91125 United States Kavli Institute for Theoretical Physics University of California Santa BarbaraCA93106 United States Center for Data Driven Discovery California Institute of Technology PasadenaCA

We present rotationally-averaged visible spectrophotometry of minimoon 2020 CD3, the second asteroid known to become temporarily captured by the Earth-Moon system’s gravitational field. The spectrophotometry was taken with Keck I/LRIS between wavelengths 434 nm and 912 nm in B, g, V, R, I and RG850 filters as it was leaving the Earth-Moon system on 2020 March 23 UTC. The broad-band spectrophotometry of 2020 CD3 most closely resembles the spectra of V-type asteroids and some Lunar rock samples with a reddish slope of ∼18%/100 nm between 434 nm and 761 nm corresponding to colors of g-r = 0.62±0.08, r-i = 0.21 ± 0.06 and an absorption band at ∼900 nm corresponding to i-z = -0.54±0.10 (DeMeo et al. 2009;Isaacson et al. 2011). Combining our measured 31.9±0.1 absolute magnitude with an albedo of 0.35 typical for V-type asteroids (DeMeo & Carry 2013), we determine 2020 CD3’s size to be ∼1.0±0.1 m making it the first minimoon and one of the smallest asteroids to be spectrally characterized. We use our time-series photometry to detect periodic lightcurve variations with a −4 false alarm probability corresponding to a lightcurve period of ∼573 s and a lightcurve amplitude of ∼1 mag implying 2020 CD3 possesses a b/a axial ratio of ∼2.5. In addition, we extend the observational arc of 2020 CD3 to 37 days between 2020 February 15 UTC and 2020 March 23 UTC. From the improved orbital solution for 2020 CD3, we estimate its likely duration of its capture to be ∼2 y, and we measure the non-gravitation perturbation on its orbit due to radiation pressure with an area-to-mass ratio of 6.9±2.4×10−4 m2/kg implying a density of 2.1±0.7 g/cm3, broadly compatible with the densities of other meter-scale asteroids (e.g., Micheli et al. 2012;Mommert et al. 2014) and Lunar rock (∼2.4 g/cm3, Kiefer et al. 2012). We searched for pre-discovery observations of 2020 CD3 in the ZTF archive as far back as 2018 October (Masci et al. 2019), but were unable to locate any positive detections. Copyright © 2

关键词： Asteroids

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Large Shape Staggering in Neutron-Deficient Bi Isotopes

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Physical Review Letters 2021年第19期127卷 192501-192501页

作者： A. Barzakh A. N. Andreyev C. Raison J. G. Cubiss P. Van Duppen S. Péru S. Hilaire S. Goriely B. Andel S. Antalic M. Al Monthery J. C. Berengut J. Bieroń M. L. Bissell A. Borschevsky K. Chrysalidis T. E. Cocolios T. Day Goodacre J.-P. Dognon M. Elantkowska E. Eliav G. J. Farooq-Smith D. V. Fedorov V. N. Fedosseev L. P. Gaffney R. F. Garcia Ruiz M. Godefroid C. Granados R. D. Harding R. Heinke M. Huyse J. Karls P. Larmonier J. G. Li (李冀光) K. M. Lynch D. E. Maison B. A. Marsh P. Molkanov P. Mosat A. V. Oleynichenko V. Panteleev P. Pyykkö M. L. Reitsma K. Rezynkina R. E. Rossel S. Rothe J. Ruczkowski S. Schiffmann C. Seiffert M. D. Seliverstov S. Sels L. V. Skripnikov M. Stryjczyk D. Studer M. Verlinde S. Wilman A. V. Zaitsevskii Petersburg Nuclear Physics Institute NRC Kurchatov Institute 188300 Gatchina Russia Department of Physics University of York York YO10 5DD United Kingdom Advanced Science Research Center Japan Atomic Energy Agency Tokai-mura Ibaraki 319-1195 Japan KU Leuven Instituut voor Kern- en Stralingsfysica B-3001 Leuven Belgium Université Paris-Saclay CEA LMCE 91680 Bruyères-le-Châtel France Institut d’Astronomie et d’Astrophysique CP-226 Université Libre de Bruxelles 1050 Brussels Belgium Department of Nuclear Physics and Biophysics Comenius University in Bratislava 84248 Bratislava Slovakia School of Physics University of New South Wales Sydney NSW 2052 Australia Instytut Fizyki Teoretycznej Uniwersytet Jagielloński ul. prof. Stanisława Łojasiewicza 11 Kraków Poland School of Physics and Astronomy The University of Manchester Manchester M13 9PL United Kingdom Van Swinderen Institute University of Groningen 9747 Groningen Netherlands CERN Esplanade des Particules 1 1211 Geneva 23 Switzerland Institut für Physik Johannes Gutenberg-Universität Mainz D-55128 Mainz Germany TRIUMF 4004 Wesbrook Mall Vancouver British Columbia V6T 2A3 Canada NIMBE CEA CNRS Universiteé Paris-Saclay CEA Saclay 91190 Gif-sur-Yvette France Poznan University of Technology Piotrowo 3 Poznan 60-965 Poland School of Chemistry Tel Aviv University 69978 Tel Aviv Israel School of Engineering and Computing University of the West of Scotland Paisley PA1 2BE United Kingdom SQUARES CP160/09 Université libre de Bruxelles Av. F.D. Roosevelt 50 1050 Brussels Belgium Department of Physics University of Gothenburg SE-412 96 Gothenburg Sweden Institute of Applied Physics and Computational Mathematics Beijing 100088 China Saint Petersburg State University 7/9 Universitetskaya nab. St. Petersburg 199034 Russia Department of Chemistry M. V. Lomonosov Moscow State University Leninskie gory 1/3 Moscow 119991 Russia Department of Chemistry University of Helsinki P.O. Box 55 (A. I. Virtasen a

The changes in the mean-square charge radius (relative to Bi209), magnetic dipole, and electric quadrupole moments of Bi187,188,189,191 were measured using the in-source resonance-ionization spectroscopy technique at ISOLDE (CERN). A large staggering in radii was found in Bi187,188,189g, manifested by a sharp radius increase for the ground state of Bi188 relative to the neighboring Bi187,189g. A large isomer shift was also observed for Bi188m. Both effects happen at the same neutron number, N=105, where the shape staggering and a similar isomer shift were observed in the mercury isotopes. Experimental results are reproduced by mean-field calculations where the ground or isomeric states were identified by the blocked quasiparticle configuration compatible with the observed spin, parity, and magnetic moment.

关键词： Nuclear charge distribution Nuclear density functional theory Nuclear spin & parity Nuclear structure & decays Spectroscopic factors & electromagnetic moments

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The Atacama Cosmology Telescope: Constraints on Cosmic Birefringence

arXiv

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arXiv 2020年

作者： Namikawa, Toshiya Guan, Yilun Darwish, Omar Sherwin, Blake D. Aiola, Simone Battaglia, Nicholas Beall, James A. Becker, Daniel T. Bond, J. Richard Calabrese, Erminia Chesmore, Grace E. Choi, Steve K. Sifón, Cristóbal Devlin, Mark J. Dunkley, Joanna Dünner, Rolando Fox, Anna E. Gallardo, Patricio A. Gluscevic, Vera Han, Dongwon Hasselfield, Matthew Hilton, Gene C. Hincks, Adam D. Hložek, Renée Hubmayr, Johannes Huffenberger, Kevin Hughes, John P. Koopman, Brian J. Kosowsky, Arthur Louis, Thibaut Lungu, Marius MacInnis, Amanda Madhavacheril, Mathew S. Mallaby-Kay, Maya Maurin, Loïc McMahon, Jeffrey Moodley, Kavilan Naess, Sigurd Nati, Federico Newburgh, Laura B. Nibarger, John P. Niemack, Michael D. Page, Lyman A. Qu, Frank J. Robertson, Naomi Schillaci, Alessandro Sehgal, Neelima Simon, Sara M. Spergel, David N. Staggs, Suzanne T. Storer, Emilie R. van Engelen, Alexander van Lanen, Jeff Wollack, Edward J. Department of Applied Mathematics and Theoretical Physics University of Cambridge Wilberforce Road CambridgeCB3 0WA United Kingdom Department of Physics and Astronomy University of Pittsburgh PittsburghPA15260 United States Center for Computational Astrophysics Flatiron Institute 162 5th Avenue New YorkNY10010 United States Department of Astronomy Cornell University IthacaNY14853 United States National Institute of Standards and Technology 325 Broadway BoulderCO80305 United States Canadian Institute for Theoretical Astrophysics University of Toronto TorontoONM5S 3H8 Canada School of Physics and Astronomy Cardiff University CardiffCF10 3AT United Kingdom Department of Physics University of Michigan Ann ArborMI48109 United States Department of Astronomy Cornell University IthacaNY14853 United States Instituto de Física Pontificia Universidad Católica de Valparaíso CasillaValparaíso4059 Chile Department of Physics and Astronomy University of Pennsylvania 209 South 33rd Street PhiladelphiaPA19104 United States Department of Astrophysical Sciences Princeton University 4 Ivy Lane PrincetonNJ08544 United States Joseph Henry Laboratories of Physics Jadwin Hall Princeton University PrincetonNJ08544 United States Instituto de Astrofísica Centro de Astro-Ingeniería Facultad de Física Pontificia Spain Universidad Católica de Chile Av. Vicuña Mackenna 4860 Macul Santiago7820436 Chile Department of Physics Cornell University IthacaNY14853 United States Department of Physics and Astronomy University of Southern California Los AngelesCA90089-0484 United States Physics and Astronomy Department Stony Brook University Stony BrookNY11794 United States Canadian Institute for Theoretical Astrophysics 60 St George St TorontoONM5S 3H8 Canada Dunlap Institute for Astronomy and Astrophysics University of Toronto 50 St George Street TorontoONM5S 3H4 Canada David A. Dunlap Department of Astronomy and Astrophysics University of Toronto 50

We present new constraints on anisotropic birefringence of the cosmic microwave background polarization using two seasons of data from the Atacama Cosmology Telescope covering 456 square degrees of sky. The birefringence power spectrum, measured using a curved-sky quadratic estimator, is consistent with zero. Our results provide the tightest current constraint on birefringence over a range of angular scales between 5 arcminutes and 9 degrees. We improve previous upper limits on the amplitude of a scale-invariant birefringence power spectrum by a factor of between 2 and 3. Assuming a nearly-massless axion field during inflation, our result is equivalent to a 2σ upper limit on the Chern-Simons coupling constant between axions and photons of gαγ −2/HI where HI is the inflationary Hubble scale. Copyright © 2020, The Authors. All rights reserved.

关键词： Birefringence

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Development of a do-it-yourself (D.I.Y.) gel electrophoresis apparatus for Grade-12 STEM general biology students

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Journal of physics: Conference Series 2021年第1期1835卷

作者： Janne Noelle L. Gamale Dharel P. Acut Karla Marie Frances P. Niere Gwen Stephany S. Silagan Ethel P. Curaraton Guadalupe C. Latonio Rhett Anthony C. Latonio Joy R. Magsayo High School Department Sotero B. Cabahug FORUM for Literacy Consolacion Cebu 6001 Philippines Applied Physics Program National Institute of Physics College of Science University of the Philippines – Diliman Roxas Ave. Diliman Quezon City 1101 Philippines Science Education Program Graduate School College of Teacher Education Cebu Normal University Osmeña Blvd. Cebu City Cebu 6000 Philippines Department of Science and Mathematics Education College of Education Mindanao State University – Iligan Institute of Technology Iligan City 9200 Philippines

A hurdle to effective science education in schools is often the lack of teaching materials. Teaching science education in the 21st century requires direct visualization and manipulation with effective use and implementation for meaningful learning to occur, thus, unleashing students' potential towards the lesson, boosting their engagement in learning, and applying the knowledge into skills. This study was carried out to develop a do-it-yourself gel electrophoresis apparatus. This study was conducted in Cebu Normal University, Philippines with nineteen (19) teachers from the Methods of Teaching Science and Instructional Trends and Issues Class who evaluated the apparatus in terms of usability and functionality. The respondents tested the Gel Electrophoresis apparatus by conducting the experiment and they evaluated the apparatus' functionality and usability by using an evaluation sheet which is composed of eleven (11) usability questions, four (4) functionality questions. Suggestions were also asked to improve the said apparatus. After gathering data, the suggestions made by the respondents were incorporated which resulted to the improved D.I.Y. Gel Electrophoresis Apparatus. A manual with the procedures was also designed to further guide students and teachers on how to build the apparatus. With the findings and results obtained in the study, the respondents recommended the usage of the developed do-it-yourself gel electrophoresis apparatus in their respective classes and agreed that it is a good source of learning the concept of gel electrophoresis as a 21st century biological technique. The apparatus was easy to set-up and is of low-cost. During experimentation, the apparatus yielded with a positive result – the separation of food dyes which follows the principle of gel electrophoresis. Moreover, the experiment encourages creativity and it helps with the understanding of the nature of DNA and the concept of gel electrophoresis as a 21st century biological skills.

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Implementation of a selective mean filter algorithm to reduce noise in computed radiography images

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AIP Conference Proceedings 2021年第1期2346卷

作者： J. H. Saragih C. Anam W. S. Budi T. I. Simarmata G. Dougherty 1Postgraduate Program Department of Physics Faculty of Sciences and Mathematics Diponegoro University Jl. Prof. Soedarto SH Tembalang Semarang 50275 Central Java Indonesia 2Department of Physics Faculty of Sciences and Mathematics Diponegoro University Jl. Prof. Soedarto SH Tembalang Semarang 50275 Central Java Indonesia 3Department of Radiology Premier Jatinegara Hospital Jl. Jatinegara Timur No. 85-87 Jatinegara Kota Jakarta Timur 13310 DKI Jakarta Indonesia 4Department of Applied Physics and Medical Imaging California State University Channel Islands Camarillo CA 93012 USA

This study implements a selective mean filter (SMF) and determines its effectiveness on computed radiography (CR) images. A phantom of the Kualitas Citra Imajing (KUCING) was used. The effectiveness of the SMF was compared to the adaptive mean filter (AMF). The assessment of image quality was based on several parameters, such as the peak signal to noise ratio (PSNR), mean squared error (MSE), structural similarity index (SSIM), contrast consistency (CV), contrast linearity (CL), and modulation transfer function (MTF). The results show that the PSNR value generated by the SMF is higher than with the AMF. The MSE value generated by the SMF algorithm is lower than AMF. The SSIM values showed that SMF algorithm produces a better image similarity between the original image and the filtered image compared to the AMF algorithm. In consistency and linearity, the AMF leads to significant changes from the original image, while the SMF image is closer to the original image. The 10% MTF generated by the SMF is the same as the original image, while AMF produces a significant decrease in the 10% MTF. The SMF took 17.9 ± 0.7 seconds for denoising one CR image, while AMF took 519 ± 5 seconds. SMF decreases image noise without a significant effect on the spatial resolution of the image. SMF filtering is superior to AMF filtering in terms of spatial resolution and a shorter computational time.

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Operational systems, logistics engineering and technology insertion

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NAVAL ENGINEERS JOURNAL 1997年第3期109卷 205-220页

作者： Grubb, MJ Skolnick, A Michael J. Grubb:has perfomzed naval engineering at the Crane Division Naval Surface Warfare Center (NSWC) for more than twenty-five years. He currently the program manager for the Sustainable Hardware and Affordable Readiness Practice Program (SHARP). is a Navy-wide logistics research and development prgram aimed at the successful transiton of proved technologies inot the fleet. SHARP focuses on reducing acquisition performance capability reliability maintainability and readiness of these systems. Mr. Grubb has served as a department director for the past eleven years. His most recent assignment was as director of the Tactical Computer Resources and Test Equipment Department. This organization provided acquisition and in-service engineering support of the Navy's tectical embedded computers priphirals displays and mass memory storage devices. The organization also provided a complete range of product engineering and metrology engineerig services for SSP NevSeaSysCom and the Trident Program. Prior to this appointment Mr. Grubb was deptuy director psysical security programs department and site responsible for program management and system integration of ashore integrated security systems. Mr. Grubb holds a B.S. degree in industrial engineering from Iowa State Universtiy an M.S. degree in industrial engineering from Purdue University and has copleted the course work (Dec.'96 for a master's degree in public and environment affairs at Indiana University-Purdue Univeristy Indianapolis. Dr. Alfred Skolnick operates System Science Consultants (SSC) specilizing in strategic planning technical program definiton technology assessment and engineering analyses on selected matters of national interest. He has taught physics mathematics and management sciences at University of Virginia and Marymount University and is currently adjunct professor of mathematics at Northern Virginia Community College. Form 1985 to 1989 he was president of the American Society of Noval Engineers. Dr. Skolnick served at Applied Physic

In an era of fiscal austerity, downsizing and unforgiving pressure upon human and economic capital, it is an Augean task to identify resources for fresh and creative work. The realities of the day and the practical demands of more immediate fleet needs can often dictate higher priorities. Yet, the Navy must avoid eating its seed corn. Exercising both technical insight and management foresight, the fleet, the R&D community, the Office of the Chief of Naval Operations (OpNav) and the product engineering expertise of the Naval Surface Warfare Center (NSWC) are joined and underway with integrated efforts to marry new, fully demonstrated technologies and operational urgencies. Defense funding today cannot sponsor all work that can be mission-justified over the long term because budgets are insufficient to support product maturation within the classical development cycle. However, by rigorous technical filtering and astute engineering of both marketplace capabilities and currently available components, it is possible in a few select cases to compress and, in effect, integrate advanced development (6.3), engineering development (6.4), weapon procurement (WPN), ship construction (SCN), operation and maintenance (O&M,N) budgetary categories when fleet criticalities and technology opportunities can happily meet. In short, 6.3 funds can be applied directly to ''ripe gateways'' so modern technology is inserted into existing troubled or aging systems, sidestepping the lengthy, traditional development cycle and accelerating practical payoffs to recurrent fleet problems. To produce such constructive results has required a remarkable convergence of sponsor prescience and engineering workforce excellence. The paper describes, extensively, the philosophy of approach, transition strategy, polling of fleet needs, technology assessment, and management team requirements. The process for culling and selecting specific candidate tasks for SHARP sponsorship (matching operational need with t

关键词： Naval vessels

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Persistent homology of the cosmic web. I: Hierarchical topology in ΛCDM cosmologies

arXiv

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arXiv 2020年

作者： Wilding, Georg Nevenzeel, Keimpe de Weygaert, Rien van Vegter, Gert Pranav, Pratyush Jones, Bernard J.T. Efstathiou, Konstantinos Feldbrugge, Job Kapteyn Astronomical Institute University of Groningen PO Box 800 Groningen9700 AV Netherlands Bernoulli Institute for Mathematics Computer Science and Artificial Intelligence University of Groningen PO Box 800 Groningen9700 AV Netherlands Centre for Data Science and Systems Complexity University of Groningen PO Box 800 Groningen9700 AV Netherlands Univ Lyon ENS de Lyon CNRS Centre de Recherche Astrophysique de Lyon UMR5574 LyonFV69007 France Technion – Israel Institute of Technology Haifa32000 Israel Division of Natural and Applied Sciences and Zu Chongzhi Center for Mathematics and Computational Science Duke Kunshan University No. 8 Duke Avenue KunshanJiangsu Province215316 China Perimeter Institute 31 Caroline St N WaterlooONN2L 2Y5 Canada Department of Physics Carnegie Mellon University 5000 Forbes Ave PittsburghPA15217 United States

Using a set of ΛCDM simulations of cosmic structure formation, we study the evolving connectivity and changing topological structure of the cosmic web using state-of-the-art tools of multiscale topological data analysis (TDA). We follow the development of the cosmic web topology in terms of the evolution of Betti number curves and feature persistence diagrams of the three (topological) classes of structural features: matter concentrations, filaments and tunnels, and voids. The Betti curves specify the prominence of features as a function of density level, and their evolution with cosmic epoch reflects the changing network connections between these structural features. The persistence diagrams quantify the longevity and stability of topological features. In this study we establish, for the first time, the link between persistence diagrams, the features they show, and the gravitationally driven cosmic structure formation process. By following the diagrams’ development over cosmic time, the link between the multiscale topology of the cosmic web and the hierarchical buildup of cosmic structure is established. The sharp apexes in the diagrams are intimately related to key transitions in the structure formation process. The apex in the matter concentration diagrams coincides with the density level at which, typically, they detach from the Hubble expansion and begin to collapse. At that level many individual islands merge to form the network of the cosmic web and a large number of filaments and tunnels emerge to establish its connecting bridges. The location trends of the apex possess a self-similar character that can be related to the cosmic web’s hierarchical buildup. We find that persistence diagrams provide a significantly higher and more profound level of information on the structure formation process than more global summary statistics like Euler characteristic or Betti numbers. Copyright © 2020, The Authors. All rights reserved.

关键词： Graphic methods

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The Atacama Cosmology Telescope: DR4 maps and cosmological parameters

arXiv

引用

arXiv 2020年

作者： Aiola, Simone Calabrese, Erminia Maurin, Loïc Naess, Sigurd Schmitt, Benjamin L. Abitbol, Maximilian H. Addison, Graeme E. Ade, Peter A.R. Alonso, David Amiri, Mandana Amodeo, Stefania Angile, Elio Austermann, Jason E. Baildon, Taylor Battaglia, Nick Beall, James A. Bean, Rachel Becker, Daniel T. Bond, J. Richard Bruno, Sarah Marie Calafut, Victoria Campusano, Luis E. Carrero, Felipe Chesmore, Grace E. Cho, Hsiao-Mei Choi, Steve K. Clark, Susan E. Cothard, Nicholas F. Crichton, Devin Crowley, Kevin T. Darwish, Omar Datta, Rahul Denison, Edward V. Devlin, Mark J. Duell, Cody J. Duff, Shannon M. Duivenvoorden, Adriaan J. Dunkley, Jo Dünner, Rolando Essinger-Hileman, Thomas Fankhanel, Max Ferraro, Simone Fox, Anna E. Fuzia, Brittany Gallardo, Patricio A. Gluscevic, Vera Golec, Joseph E. Grace, Emily Gralla, Megan Guan, Yilun Hall, Kirsten Halpern, Mark Han, Dongwon Hargrave, Peter Hasselfield, Matthew Helton, Jakob M. Henderson, Shawn Hensley, Brandon Hill, J. Colin Hilton, Gene C. Hilton, Matt Hincks, Adam D. Hložek, Renée Ho, Shuay-Pwu Patty Hubmayr, Johannes Huffenberger, Kevin M. Hughes, John P. Infante, Leopoldo Irwin, Kent Jackson, Rebecca Klein, Jeff Knowles, Kenda Koopman, Brian Kosowsky, Arthur Lakey, Victoria Li, Dale Li, Yaqiong Li, Zack Lokken, Martine Louis, Thibaut Lungu, Marius MacInnis, Amanda Madhavacheril, Mathew Maldonado, Felipe Mallaby-Kay, Maya Marsden, Danica McMahon, Jeff Menanteau, Felipe Moodley, Kavilan Morton, Tim Namikawa, Toshiya Nati, Federico Newburgh, Laura Nibarger, John P. Nicola, Andrina Niemack, Michael D. Nolta, Michael R. Orlowski-Sherer, John Page, Lyman A. Pappas, Christine G. Partridge, Bruce Phakathi, Phumlani Pisano, Giampaolo Prince, Heather Puddu, Roberto Qu, Frank J. Rivera, Jesus Robertson, Naomi Rojas, Felipe Salatino, Maria Schaan, Emmanuel Schillaci, Alessandro Sehgal, Neelima Sherwin, Blake D. Sierra, Carlos Sievers, Jon Sifon, Cristobal Sikhosana, Precious Simon, Sara Spergel, David N. Staggs, Suzanne T. Stevens, Jason Storer, Emilie Sunder, Dhaneshwar D. Switzer, Center for Computational Astrophysics Flatiron Institute 162 5th Avenue New YorkNY10010 United States Joseph Henry Laboratories of Physics Jadwin Hall Princeton University PrincetonNJ08544 United States School of Physics and Astronomy Cardiff University The Parade Wales CardiffCF24 3AA United Kingdom Université Paris-Saclay CNRS Institut d'astrophysique spatiale Orsay 91405 France Instituto de Astrofísica Centro de Astro-Ingeniería Facultad de Fìsica Pontificia Universidad Católica de Chile Av. Vicuña Mackenna 4860 Macul Santiago7820436 Chile Department of Physics and Astronomy University of Pennsylvania 209 South 33rd Street PhiladelphiaPA19104 United States Department of Physics University of Oxford Keble Road OxfordOX1 3RH United Kingdom Dept. of Physics and Astronomy The Johns Hopkins University 3400 N. Charles St. BaltimoreMD21218-2686 United States Department of Physics and Astronomy University of British Columbia VancouverBCV6T 1Z4 Canada Department of Astronomy Cornell University IthacaNY14853 United States NIST Quantum Devices Group 325 Broadway Mailcode 817.03 BoulderCO80305 United States Department of Physics University of Michigan Ann Arbor48103 United States Canadian Institute for Theoretical Astrophysics University of Toronto TorontoONM5S 3H8 Canada Universidad de Chile Dept Astronomía Casilla Santiago36-D Chile Sociedad Radiosky Asesorías de Ingeniería Limitada Camino a Toconao 145-A Ayllu de Solor San Pedro de Atacama Chile Department of Physics University of Chicago ChicagoIL60637 United States SLAC National Accelerator Laboratory 2575 Sand Hill Road Menlo ParkCA94025 United States Department of Physics Cornell University IthacaNY14853 United States Institute for Advanced Study 1 Einstein Dr PrincetonNJ08540 United States Department of Applied and Engineering Physics Cornell University IthacaNY14853 United States Astrophysics Research Centre School of Mathematics Statistics and Computer Scie

We present new arcminute-resolution maps of the Cosmic Microwave Background temperature and polarization anisotropy from the Atacama Cosmology Telescope, using data taken from 2013-2016 at 98 and 150 GHz. The maps cover more than 17,000 deg2, the deepest 600 deg2 with noise levels below 10µK-arcmin. We use the power spectrum derived from almost 6,000 deg2 of these maps to constrain cosmology. The ACT data enable a measurement of the angular scale of features in both the divergence-like polarization and the temperature anisotropy, tracing both the velocity and density at last-scattering. From these one can derive the distance to the last-scattering surface and thus infer the local expansion rate, H0. By combining ACT data with large-scale information from WMAP we measure H0 = 67.6±1.1 km/s/Mpc, at 68% confidence, in excellent agreement with the independently-measured Planck satellite estimate (from ACT alone we find H0 = 67.9 ±1.5 km/s/Mpc). The ΛCDM model provides a good fit to the ACT data, and we find no evidence for deviations: both the spatial curvature, and the departure from the standard lensing signal in the spectrum, are zero to within 1σ;the number of relativistic species, the primordial Helium fraction, and the running of the spectral index are consistent with ΛCDM predictions to within 1.5-2.2σ. We compare ACT, WMAP, and Planck at the parameter level and find good consistency;we investigate how the constraints on the correlated spectral index and baryon density parameters readjust when adding CMB large-scale information that ACT does not measure. The DR4 products presented here will be publicly released on the NASA Legacy Archive for Microwave Background Data Analysis. Copyright © 2020, The Authors. All rights reserved.

关键词： Cosmology

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The Atacama Cosmology Telescope: A measurement of the cosmic microwave background power spectra at 98 and 150 GHZ

arXiv

引用

arXiv 2020年

作者： Choi, Steve K. Hasselfield, Matthew Ho, Shuay-Pwu Patty Koopman, Brian Lungu, Marius Abitbol, Maximilian H. Addison, Graeme E. Ade, Peter A.R. Aiola, Simone Alonso, David Amiri, Mandana Amodeo, Stefania Angile, Elio Austermann, Jason E. Baildon, Taylor Battaglia, Nick Beall, James A. Bean, Rachel Becker, Daniel T. Bond, J. Richard Bruno, Sarah Marie Calabrese, Erminia Calafut, Victoria Campusano, Luis E. Carrero, Felipe Chesmore, Grace E. Cho, Hsiao-Mei Clark, Susan E. Cothard, Nicholas F. Crichton, Devin Crowley, Kevin T. Darwish, Omar Datta, Rahul Denison, Edward V. Devlin, Mark J. Duell, Cody J. Duff, Shannon M. Duivenvoorden, Adriaan J. Dunkley, Jo Dünner, Rolando Essinger-Hileman, Thomas Fankhanel, Max Ferraro, Simone Fox, Anna E. Fuzia, Brittany Gallardo, Patricio A. Gluscevic, Vera Golec, Joseph E. Grace, Emily Gralla, Megan Guan, Yilun Hall, Kirsten Halpern, Mark Han, Dongwon Hargrave, Peter Henderson, Shawn Hensley, Brandon Hill, J. Colin Hilton, Gene C. Hilton, Matt Hincks, Adam D. Hložek, Renée Hubmayr, Johannes Huffenberger, Kevin M. Hughes, John P. Infante, Leopoldo Irwin, Kent Jackson, Rebecca Klein, Jeff Knowles, Kenda Kosowsky, Arthur Lakey, Victoria Li, Dale Li, Yaqiong Li, Zack Lokken, Martine Louis, Thibaut MacInnis, Amanda Madhavacheril, Mathew Maldonado, Felipe Mallaby-Kay, Maya Marsden, Danica Maurin, Loïc McMahon, Jeff Menanteau, Felipe Moodley, Kavilan Morton, Tim Naess, Sigurd Namikawa, Toshiya Nati, Federico Newburgh, Laura Nibarger, John P. Nicola, Andrina Niemack, Michael D. Nolta, Michael R. Orlowski-Sherer, John Page, Lyman A. Pappas, Christine G. Partridge, Bruce Phakathi, Phumlani Prince, Heather Puddu, Roberto Qu, Frank J. Rivera, Jesus Robertson, Naomi Rojas, Felipe Salatino, Maria Schaan, Emmanuel Schillaci, Alessandro Schmitt, Benjamin L. Sehgal, Neelima Sherwin, Blake D. Sierra, Carlos Sievers, Jon Sifon, Cristobal Sikhosana, Precious Simon, Sara Spergel, David N. Staggs, Suzanne T. Stevens, Jason Storer, Emilie Sunder, Dhaneshwar D. Switzer, Eric R. Thorne, Ben Thornton, Robe Department of Physics Cornell University IthacaNY14853 United States Department of Astronomy Cornell University IthacaNY14853 United States Joseph Henry Laboratories of Physics Jadwin Hall Princeton University PrincetonNJ08544 United States Center for Computational Astrophysics Flatiron Institute 162 5th Avenue New YorkNY10010 United States Department of Astronomy and Astrophysics The Pennsylvania State University University ParkPA16802 United States Institute for Gravitation and the Cosmos The Pennsylvania State University University ParkPA16802 United States Department of Physics Yale University 217 Prospect St New HavenCT06511 United States Department of Physics and Astronomy University of Pennsylvania 209 South 33rd Street PhiladelphiaPA19104 United States Department of Physics University of Oxford Keble Road OxfordOX1 3RH United Kingdom Dept. of Physics and Astronomy The Johns Hopkins University 3400 N. Charles St. BaltimoreMD21218-2686 United States School of Physics and Astronomy Cardiff University The Parade Wales CardiffCF24 3AA United Kingdom Department of Physics and Astronomy University of British Columbia VancouverBCV6T 1Z4 Canada NIST Quantum Devices Group 325 Broadway Mailcode 817.03 BoulderCO80305 United States Department of Physics University of Michigan Ann Arbor48103 United States Canadian Institute for Theoretical Astrophysics University of Toronto TorontoONM5S 3H8 Canada Universidad de Chile Dept Astronomía Casilla Santiago36-D Chile Sociedad Radiosky Asesorías de Ingeniería Limitada Camino a Toconao 145-A Ayllu de Solor San Pedro de Atacama Chile Department of Physics University of Chicago ChicagoIL60637 United States SLAC National Accelerator Laboratory 2575 Sand Hill Road Menlo ParkCA94025 United States Institute for Advanced Study 1 Einstein Dr PrincetonNJ08540 United States Department of Applied and Engineering Physics Cornell University IthacaNY14853 United States Astrophysics Res

We present the temperature and polarization angular power spectra of the CMB measured by the Atacama Cosmology Telescope (ACT) from 5400 deg2 of the 2013-2016 survey, which covers >15000 deg2 at 98 and 150 GHz. For this analysis we adopt a blinding strategy to help avoid confirmation bias and, related to this, show numerous checks for systematic error done before unblinding. Using the likelihood for the cosmological analysis we constrain secondary sources of anisotropy and foreground emission, and derive a "CMB-only" spectrum that extends to = 4000. At large angular scales, foreground emission at 150 GHz is ∼1% of TT and EE within our selected regions and consistent with that found by Planck. Using the same likelihood, we obtain the cosmological parameters for ΛCDM for the ACT data alone with a prior on the optical depth of τ = 0.065 ± 0.015. ΛCDM is a good fit. The best-fit model has a reduced χ2 of 1.07 (PTE = 0.07) with H0 = 67.9 ± 1.5 km/s/Mpc. We show that the lensing BB signal is consistent with ΛCDM and limit the celestial EB polarization angle to ψP = −0.07◦ ± 0.09◦. We directly cross correlate ACT with Planck and observe generally good agreement but with some discrepancies in TE. All data on which this analysis is based will be publicly released. Copyright © 2020, The Authors. All rights reserved.

关键词： Cosmology

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Free-energy landscapes of DNA and its assemblies: Perspectives from coarse-grained modelling

arXiv

引用

arXiv 2021年

作者： Doye, Jonathan P.K. Louis, Ard A. Schreck, John S. Romano, Flavio Harrison, Ryan M. Mosayebi, Majid Engel, Megan C. Ouldridge, Thomas E. Physical and Theoretical Chemistry Laboratory Department of Chemistry University of Oxford OxfordOX1 3QZ United Kingdom Rudolf Peierls Centre for Theoretical Physics University of Oxford Parks Road OxfordOX1 3PU United Kingdom National Center for Atmospheric Research Computational and Information Systems Laboratory 850 Table Mesa Drive BoulderCO80305 United States Dipartimento di Scienze Molecolari e Nanosistemi Università Ca' Foscari di Venezia via Torino 155 Venezia Mestre30170 Italy School of Mathematics University of Bristol BristolBS8 1QU United Kingdom School of Engineering and Applied Sciences Harvard University 29 Oxford Street CambridgeMA02138 United States Department of Bioengineering and Centre for Synthetic Biology Imperial College London LondonSW7 2AZ United Kingdom

This chapter will provide an overview of how characterizing free-energy landscapes can provide insights into the biophysical properties of DNA, as well as into the behaviour of the DNA assemblies used in the field of DNA nanotechnology. The landscapes for these complex systems are accessible through the use of accurate coarse-grained descriptions of DNA. Particular foci will be the landscapes associated with DNA self-assembly and mechanical deformation, where the latter can arise from either externally imposed forces or internal stresses. © 2021, CC BY.

关键词： DNA

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