42,237 research outputs found
CLIMATE CHANGE AND GLOBAL ECONOMIC STATUS. PRESENT AND PERSPECTIVES
Climate change, currently affecting the entire planet, is considered by the specialists the result of the increase in anthropogenic GHG concentrations. Sectors such as agriculture, transport, energy, tourism and also food security, population health, water resources, and ecosystems become vulnerable to the changes in climate. The climate change could generate costs and benefits for the Romanian seaside and mountain tourism, the multiple linear regression models proving that the tourism demand (arrivals and overnights) is depending on tourism offer (bed-places’ number, tourism capacity in function), but also on climate parameters (air temperature, layer of snow).climate change, costs, economy, tourism
Status of the joint LIGO--TAMA300 inspiral analysis
We present the status of the joint search for gravitational waves from
inspiraling neutron star binaries in the LIGO Science Run 2 and TAMA300 Data
Taking Run 8 data, which was taken from February 14 to April 14, 2003, by the
LIGO and TAMA collaborations. In this paper we discuss what has been learned
from an analysis of a subset of the data sample reserved as a ``playground''.
We determine the coincidence conditions for parameters such as the coalescence
time and chirp mass by injecting simulated Galactic binary neutron star signals
into the data stream. We select coincidence conditions so as to maximize our
efficiency of detecting simulated signals. We obtain an efficiency for our
coincident search of 78 %, and show that we are missing primarily very distant
signals for TAMA300. We perform a time slide analysis to estimate the
background due to accidental coincidence of noise triggers. We find that the
background triggers have a very different character from the triggers of
simulated signals.Comment: 10 page, 8 figures, accepted for publication in Classical and Quantum
Gravity for the special issue of the GWDAW9 Proceedings ; Corrected typos,
minor change
Recent results on the search for continuous sources with LIGO and GEO600
An overview of the searches for continuous gravitational wave signals in LIGO
and GEO 600 performed on different recent science runs and results are
presented. This includes both searching for gravitational waves from known
pulsars as well as blind searches over a wide parameter space.Comment: TAUP2005 Proceedings to be published in Journal of Physics:
Conference Serie
Observing gravitational-wave transient GW150914 with minimal assumptions
The gravitational-wave signal GW150914 was first identified on September 14, 2015, by searches for short-duration gravitational-wave transients. These searches identify time-correlated transients in multiple detectors with minimal assumptions about the signal morphology, allowing them to be sensitive to gravitational waves emitted by a wide range of sources including binary black hole mergers. Over the observational period from September 12 to October 20, 2015, these transient searches were sensitive to binary black hole mergers similar to GW150914 to an average distance of ∼600 Mpc. In this paper, we describe the analyses that first detected GW150914 as well as the parameter estimation and waveform reconstruction techniques that initially identified GW150914 as the merger of two black holes. We find that the reconstructed waveform is consistent with the signal from a binary black hole merger with a chirp mass of ∼30 M and a total mass before merger of ∼70 M in the detector frame.The authors gratefully acknowledge the support of the
United States National Science Foundation (NSF) for the
construction and operation of the LIGO Laboratory and
Advanced LIGO as well as the Science and Technology
Facilities Council (STFC) of the United Kingdom, the MaxPlanck-Society
(MPS), and the State of Niedersachsen/
Germany for support of the construction of Advanced
LIGO and construction and operation of the GEO 600
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 Foundation for
Fundamental Research on Matter supported by the
Netherlands Organisation for Scientific Research, 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, Department of Science and
Technology, India; Science & Engineering Research Board
(SERB), India; Ministry of Human Resource Development,
India; the Spanish Ministerio de Economía y Competitividad;
the Conselleria d’Economia i Competitivitat and Conselleria
d’Educació; Cultura i Universitats of the Govern de les Illes
Balears; the National Science Centre of Poland; the European
Commission; the Royal Society; the Scottish Funding
Council; the Scottish Universities Physics Alliance; the
Hungarian Scientific Research Fund (OTKA); the Lyon
Institute of Origins (LIO); the National Research
Foundation of Korea; Industry Canada and the Province of
Ontario through the Ministry of Economic Development and
Innovation; the National Science and Engineering Research
Council Canada; Canadian Institute for Advanced Research;
the Brazilian Ministry of Science, Technology, and Innovation; Russian Foundation for Basic Research; the
Leverhulme Trust; the Research Corporation; Ministry of
Science and Technology (MOST), Taiwan; and the Kavli
Foundation. The authors gratefully acknowledge the support of the NSF, STFC, MPS, INFN, CNRS and the State of
Niedersachsen/Germany for provision of computational
resources. This article has been assigned the document
number LIGO-P1500229
Massive Gravity on de Sitter and Unique Candidate for Partially Massless Gravity
We derive the decoupling limit of Massive Gravity on de Sitter in an
arbitrary number of space-time dimensions d. By embedding d-dimensional de
Sitter into d+1-dimensional Minkowski, we extract the physical helicity-1 and
helicity-0 polarizations of the graviton. The resulting decoupling theory is
similar to that obtained around Minkowski. We take great care at exploring the
partially massless limit and define the unique fully non-linear candidate
theory that is free of the helicity-0 mode in the decoupling limit, and which
therefore propagates only four degrees of freedom in four dimensions. In the
latter situation, we show that a new Vainshtein mechanism is at work in the
limit m^2\to 2 H^2 which decouples the helicity-0 mode when the parameters are
different from that of partially massless gravity. As a result, there is no
discontinuity between massive gravity and its partially massless limit, just in
the same way as there is no discontinuity in the massless limit of massive
gravity. The usual bounds on the graviton mass could therefore equivalently
well be interpreted as bounds on m^2-2H^2. When dealing with the exact
partially massless parameters, on the other hand, the symmetry at m^2=2H^2
imposes a specific constraint on matter. As a result the helicity-0 mode
decouples without even the need of any Vainshtein mechanism.Comment: 30 pages. Some clarifications and references added. New subsection
'Symmetry and Counting in the Full Theory' added. New appendix 'St\"uckelberg
fields in the Na\"ive approach' added. Matches version published in JCA
Search for Electromagnetic Counterparts to LIGO-Virgo Candidates: Expanded Very Large Array
This paper summarizes a search for radio wavelength counterparts to candidate
gravitational wave events. The identification of an electromagnetic counterpart
could provide a more complete understanding of a gravitational wave event,
including such characteristics as the location and the nature of the
progenitor. We used the Expanded Very Large Array (EVLA) to search six galaxies
which were identified as potential hosts for two candidate gravitational wave
events. We summarize our procedures and discuss preliminary results.Comment: 4 pages; to appear in the New Horizons in Time Domain Astronomy,
Proceedings of IAU Symposium 285, eds. R. E. M. Griffin, R. J. Hanisch & R.
Seama
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