203 research outputs found
Measuring CMB Polarization with BOOMERANG
BOOMERANG is a balloon-borne telescope designed for long duration (LDB)
flights around Antarctica. The second LDB Flight of BOOMERANG took place in
January 2003. The primary goal of this flight was to measure the polarization
of the CMB. The receiver uses polarization sensitive bolometers at 145 GHz.
Polarizing grids provide polarization sensitivity at 245 and 345 GHz. We
describe the BOOMERANG telescope noting changes made for 2003 LDB flight, and
discuss some of the issues involved in the measurement of polarization with
bolometers. Lastly, we report on the 2003 flight and provide an estimate of the
expected results.Comment: 12 pages, 8 figures, To be published in the proceedings of "The
Cosmic Microwave Background and its Polarization", New Astronomy Reviews,
(eds. S. Hanany and K.A. Olive). Fixed typos, and reformatted citation
Astronomical Distance Determination in the Space Age: Secondary Distance Indicators
The formal division of the distance indicators into primary and secondary leads to difficulties in description of methods which can actually be used in two ways: with, and without the support of the other methods for scaling. Thus instead of concentrating on the scaling requirement we concentrate on all methods of distance determination to extragalactic sources which are designated, at least formally, to use for individual sources. Among those, the Supernovae Ia is clearly the leader due to its enormous success in determination of the expansion rate of the Universe. However, new methods are rapidly developing, and there is also a progress in more traditional methods. We give a general overview of the methods but we mostly concentrate on the most recent developments in each field, and future expectations. © 2018, The Author(s)
On the Synthesis of Mobile Robots Algorithms: the Case of Ring Gathering
International audienceRecent advances in Distributed Computing highlight models and algorithms for autonomous swarms of mobile robots that self-organize and cooperate to solve global objectives. The overwhelming majority of works so far considers handmade algorithms and correctness proofs.This paper is the first to propose a formal framework to automatically design distributed algorithms that are dedicated to autonomous mobile robots evolving in a discrete space. As a case study, we consider the problem of gathering all robots at a particular location, not known beforehand. Our contribution is threefold. First, we propose an encoding of the gathering problem as a reachability game. Then, we automatically generate an optimal distributed algorithm for three robots evolving on a fixed size uniform ring. Finally, we prove by induction that the generated algorithm is also correct for any ring size except when an impossibility result holds (that is, when the number of robots divides the ring size)
Global maps of soil temperature
Research in global change ecology relies heavily on global climatic grids derived from estimates of air temperature in open areas at around 2 m above the ground. These climatic grids do not reflect conditions below vegetation canopies and near the ground surface, where critical ecosystem functions occur and most terrestrial species reside. Here, we provide global maps of soil temperature and bioclimatic variables at a 1-km2 resolution for 0–5 and 5–15 cm soil depth. These maps were created by calculating the difference (i.e. offset) between in situ soil temperature measurements, based on time series from over 1200 1-km2 pixels (summarized from 8519 unique temperature sensors) across all the world's major terrestrial biomes, and coarse-grained air temperature estimates from ERA5-Land (an atmospheric reanalysis by the European Centre for Medium-Range Weather Forecasts). We show that mean annual soil temperature differs markedly from the corresponding gridded air temperature, by up to 10°C (mean = 3.0 ± 2.1°C), with substantial variation across biomes and seasons. Over the year, soils in cold and/or dry biomes are substantially warmer (+3.6 ± 2.3°C) than gridded air temperature, whereas soils in warm and humid environments are on average slightly cooler (−0.7 ± 2.3°C). The observed substantial and biome-specific offsets emphasize that the projected impacts of climate and climate change on near-surface biodiversity and ecosystem functioning are inaccurately assessed when air rather than soil temperature is used, especially in cold environments. The global soil-related bioclimatic variables provided here are an important step forward for any application in ecology and related disciplines. Nevertheless, we highlight the need to fill remaining geographic gaps by collecting more in situ measurements of microclimate conditions to further enhance the spatiotemporal resolution of global soil temperature products for ecological applications
Emission of single and few electrons in XENON1T and limits on light dark matter
Delayed single- and few-electron emissions plague dual-phase time projection chambers, limiting their potential to search for light-mass dark matter. This paper examines the origins of these events in the XENON1T experiment. Characterization of the intensity of delayed electron backgrounds shows that the resulting emissions are correlated, in time and position, with high-energy events and can effectively be vetoed. In this work we extend previous S2-only analyses down to a single electron. From this analysis, after removing the correlated backgrounds, we observe rates <30 events/(electron×kg×day) in the region of interest spanning 1 to 5 electrons. We derive 90% confidence upper limits for dark matter-electron scattering, first direct limits on the electric dipole, magnetic dipole, and anapole interactions, and bosonic dark matter models, where we exclude new parameter space for dark photons and solar dark photons
Trust in scientists and their role in society across 68 countries
Science is crucial for evidence-based decision-making. Public trust in scientists can help decision makers act on the basis of the best available evidence, especially during crises. However, in recent years the epistemic authority of science has been challenged, causing concerns about low public trust in scientists. We interrogated these concerns with a preregistered 68-country survey of 71,922 respondents and found that in most countries, most people trust scientists and agree that scientists should engage more in society and policymaking. We found variations between and within countries, which we explain with individual- and country-level variables, including political orientation. While there is no widespread lack of trust in scientists, we cannot discount the concern that lack of trust in scientists by even a small minority may affect considerations of scientific evidence in policymaking. These findings have implications for scientists and policymakers seeking to maintain and increase trust in scientists
Perceptions of science, science communication, and climate change attitudes in 68 countries – the TISP dataset
Science is integral to society because it can inform individual, government, corporate, and civil society decision-making on issues such as public health, new technologies or climate change. Yet, public distrust and populist sentiment challenge the relationship between science and society. To help researchers analyse the science-society nexus across different geographical and cultural contexts, we undertook a cross-sectional population survey resulting in a dataset of 71,922 participants in 68 countries. The data were collected between November 2022 and August 2023 as part of the global Many Labs study “Trust in Science and Science-Related Populism” (TISP). The questionnaire contained comprehensive measures for individuals’ trust in scientists, science-related populist attitudes, perceptions of the role of science in society, science media use and communication behaviour, attitudes to climate change and support for environmental policies, personality traits, political and religious views and demographic characteristics. Here, we describe the dataset, survey materials and psychometric properties of key variables. We encourage researchers to use this unique dataset for global comparative analyses on public perceptions of science and its role in society and policy-making
Constraints on the Cosmic Expansion History from GWTC-3
This material is based upon work supported by NSFʼs LIGO
Laboratory, which is a major facility fully funded by the National
Science Foundation. The authors also gratefully acknowledge the
support of the Science and Technology Facilities Council (STFC)
of the United Kingdom, the Max-Planck-Society (MPS), and the
State of Niedersachsen/Germany for support of the construction
of Advanced LIGO and construction and operation of the
GEO600 detector. Additional support for Advanced LIGO was
provided by the Australian Research Council. The authors
gratefully acknowledge the Italian Istituto Nazionale di Fisica
Nucleare (INFN), the French Centre National de la Recherche
Scientifique (CNRS), and the Netherlands Organization for
Scientific Research (NWO), for the construction and operation
of the Virgo detector and the creation and support of the EGO
consortium. The authors also gratefully acknowledge research
support from these agencies as well as by the Council of Scientific
and Industrial Research of India, the Department of Science and
Technology, India, the Science & Engineering Research Board
(SERB), India, the Ministry of Human Resource Development,
India, the Spanish Agencia Estatal de Investigación (AEI), the
Spanish Ministerio de Ciencia e Innovación and Ministerio de
Universidades, the Conselleria de Fons Europeus, Universitat i
Cultura and the Direcció General de Política Universitaria i
Recerca del Govern de les Illes Balears, the Conselleria
d’Innovació Universitats, Ciència i Societat Digital de la
Generalitat Valenciana and the CERCA Programme Generalitat
de Catalunya, Spain, the National Science Centre of Poland and
the European Union–European Regional Development Fund,
Foundation for Polish Science (FNP), the Swiss National Science
Foundation (SNSF), the Russian Foundation for Basic Research,
the Russian Science Foundation, the European Commission, the
European Social Funds (ESF), the European Regional Develop-
ment Funds (ERDF), the Royal Society, the Scottish Funding
Council, the Scottish Universities Physics Alliance, the Hungarian
Scientific Research Fund (OTKA), the French Lyon Institute of
Origins (LIO), the Belgian Fonds de la Recherche Scientifique
(FRS-FNRS), Actions de Recherche Concertées (ARC) and
Fonds Wetenschappelijk Onderzoek–Vlaanderen (FWO), Bel-
gium, the Paris Île-de-France Region, the National Research,
Development and Innovation Office Hungary (NKFIH), the
National Research Foundation of Korea, the Natural Science and
Engineering Research Council Canada, Canadian Foundation for
Innovation (CFI), the Brazilian Ministry of Science, Technology,
and Innovations, the International Center for Theoretical Physics
South American Institute for Fundamental Research (ICTP-
SAIFR), the Research Grants Council of Hong Kong, the National
Natural Science Foundation of China (NSFC), the Leverhulme
Trust, the Research Corporation, the Ministry of Science and
Technology (MOST), Taiwan, the United States Department of
Energy, and the Kavli Foundation. The authors gratefully
acknowledge the support of the NSF, STFC, INFN, and CNRS
for provision of computational resources.
This work was supported by MEXT, JSPS Leading-edge
Research Infrastructure Program, JSPS Grant-in-Aid for
Specially Promoted Research 26000005, JSPS Grant-in-Aid
for Scientific Research on Innovative Areas 2905:
JP17H06358, JP17H06361, and JP17H06364, JSPS Core-to-
Core Program A. Advanced Research Networks, JSPS Grant-
in-Aid for Scientific Research (S) 17H06133 and 20H05639,
JSPS Grant-in-Aid for Transformative Research Areas (A)
20A203: JP20H05854, the joint research program of the
Institute for Cosmic Ray Research, University of Tokyo,
National Research Foundation (NRF) and Computing Infra-
structure Project of KISTI-GSDC in Korea, Academia Sinica
(AS), AS Grid Center (ASGC), and the Ministry of Science and
Technology (MoST) in Taiwan under grants including AS-
CDA-105-M06, Advanced Technology Center (ATC) of
NAOJ, Mechanical Engineering Center of KEK.
We would like to thank all of the essential workers who put
their health at risk during the COVID-19 pandemic, without
whom we would not have been able to complete this work.Peer reviewe
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