scholarly journals Status of Advanced Virgo

2018 ◽  
Vol 182 ◽  
pp. 02003
Author(s):  
F. Acernese ◽  
T. Adams ◽  
K. Agatsuma ◽  
L. Aiello ◽  
A. Allocca ◽  
...  

The LIGO and the Virgo collaborations have recently announced the first detections of Gravitational Waves. Due to their weak amplitude, Gravitational Waves are expected to produce a very small effect on free-falling masses, which undergo a displacement of the order of 10-18 m for a Km-scale mutual distance. This discovery showed that interferometric detectors are suitable to reveal such a feeble effect, and therefore represent a new tool for astronomy, astrophysics and cosmology in the understanding of the Universe. To better reconstruct the position of the Gravitational Wave source and increase the signal-to-noise ratio of the events by means of multiple coincidence, a network of detectors is necessary. In the USA, the LIGO project has recently concluded its second Observation Run (O2) with a couple of twin 4 kilometer-long arms detectors which are placed in Washington State and Louisiana. Advanced VIRGO (AdV) is a 3 kilometer-long arms second generation interferometer situated in Cascina, near Pisa in Italy. The installation of AdV has been completed in 2016, and the first commissioning phase allowed to get to the target early-stage sensitivity, which was sufficient to join LIGO in the O2 scientific run. In this paper, the challenges of the commissioning of AdV will be presented, together with its current performances and future perspectives. Finally, in the last paragraph the latest discoveries that occurred after the ICNFP 2017 conference will be also described.

2019 ◽  
Vol 489 (3) ◽  
pp. 3294-3306 ◽  
Author(s):  
R Calvi ◽  
J M Rodríguez Espinosa ◽  
J M Mas-Hesse ◽  
K Chanchaiworawit ◽  
R Guzman ◽  
...  

ABSTRACT The epoch corresponding to a redshift of z ∼ 6.5 is close to full re-ionization of the Universe, and early enough to provide an intriguing environment to observe the early stage of large-scale structure formation. It is also an epoch that can be used to verify the abundance of a large population of low luminosity star-forming galaxies that are deemed responsible for cosmic re-ionization. Here, we present the results of follow-up multi-object spectroscopy using OSIRIS at Gran Telescopio Canarias of 16 Ly α emitter (LAE) candidates discovered in the Subaru/XMM Newton Deep Survey. We have securely confirmed 10 LAEs with sufficient signal-to-noise ratio of the Ly α emission line. The inferred star formation rates of the confirmed LAEs are on the low side, within the range 0.9–4.7 M⊙ yr−1. However, they show relatively high Ly α rest frame equivalent widths. Finally we have shown that the mechanical energy released by the star formation episodes in these galaxies is enough to create holes in the neutral hydrogen medium such that Lyman continuum photons can escape to the intergalactic medium, thus contributing to the re-ionization of the Universe.


Author(s):  
David M. Wittman

General relativity explains much more than the spacetime around static spherical masses.We briefly assess general relativity in the larger context of physical theories, then explore various general relativistic effects that have no Newtonian analog. First, source massmotion gives rise to gravitomagnetic effects on test particles.These effects also depend on the velocity of the test particle, which has substantial implications for orbits around black holes to be further explored in Chapter 20. Second, any changes in the sourcemass ripple outward as gravitational waves, and we tell the century‐long story from the prediction of gravitational waves to their first direct detection in 2015. Third, the deflection of light by galaxies and clusters of galaxies allows us to map the amount and distribution of mass in the universe in astonishing detail. Finally, general relativity enables modeling the universe as a whole, and we explore the resulting Big Bang cosmology.


2021 ◽  
Vol 39 (28_suppl) ◽  
pp. 145-145
Author(s):  
Catherine R. Fedorenko ◽  
Karma L. Kreizenbeck ◽  
Li Li ◽  
Laura Elizabeth Panattoni ◽  
Veena Shankaran ◽  
...  

145 Background: The COVID-19 pandemic disrupted medical care, including routine cancer screening for breast, colorectal, lung and cervical cancers. We aimed to investigate the impact of the pandemic on stage at diagnosis for cancer patients. Methods: Using data from the Washington State SEER records we compared AJCC stage for patients diagnosed with cancer in 2017-2019 to 2020 for two time periods, March to June (initial pandemic months) and July to December (later pandemic months). Patients were included if they were age 18+, diagnosed with a solid tumor, and not diagnosed at autopsy. Results: In the early phase of the pandemic, March – June 2020, there was a shift to cancers being diagnosed at a later stage compared to the same time period in 2017-2019 (Stage III: 13.5% to 14.9%, Stage IV: 16.2% to 19.7%). There was also a decrease in cancer diagnoses for cancers that are often detected through routine screening. As a percentage of all cancer diagnoses, both melanoma (13.2% to 9.8%) and colon cancer diagnoses (7.2% to. 6.7%) decreased during the early pandemic. In the later phase of the pandemic, July to December 2020, the stage at diagnosis showed an indication of returning to pre-pandemic levels with an increase in the proportion of early stage cancers (In situ: 16.6% to 19.3%, Stage I: 38.8% to 41.1%). Stage at diagnosis trends varied by tumor type. For colorectal cancer, the overall number of diagnoses decreased during the initial pandemic months. Stage I diagnoses decreased and Stage IV cancer diagnoses increased in both early and late stages of the pandemic. Conclusions: In Washington State, the COVID-19 pandemic had an impact on stage at diagnosis potentially caused by delays or interruptions in medical care. Additional studies are needed to understand how this shift in stage at diagnosis impacted treatment and outcomes for patients.


Author(s):  
Gianfranco Bertone

The spectacular advances of modern astronomy have opened our horizon on an unexpected cosmos: a dark, mysterious Universe, populated by enigmatic entities we know very little about, like black holes, or nothing at all, like dark matter and dark energy. In this book, I discuss how the rise of a new discipline dubbed multimessenger astronomy is bringing about a revolution in our understanding of the cosmos, by combining the traditional approach based on the observation of light from celestial objects, with a new one based on other ‘messengers’—such as gravitational waves, neutrinos, and cosmic rays—that carry information from otherwise inaccessible corners of the Universe. Much has been written about the extraordinary potential of this new discipline, since the 2017 Nobel Prize in physics was awarded for the direct detection of gravitational waves. But here I will take a different angle and explore how gravitational waves and other messengers might help us break the stalemate that has been plaguing fundamental physics for four decades, and to consolidate the foundations of modern cosmology.


2018 ◽  
Vol 168 ◽  
pp. 01008 ◽  
Author(s):  
Rong-Gen Cai ◽  
Tao Yang

The gravitational waves from compact binary systems are viewed as a standard siren to probe the evolution of the universe. This paper summarizes the potential and ability to use the gravitational waves to constrain the cosmological parameters and the dark sector interaction in the Gaussian process methodology. After briefly introducing the method to reconstruct the dark sector interaction by the Gaussian process, the concept of standard sirens and the analysis of reconstructing the dark sector interaction with LISA are outlined. Furthermore, we estimate the constraint ability of the gravitational waves on cosmological parameters with ET. The numerical methods we use are Gaussian process and the Markov-Chain Monte-Carlo. Finally, we also forecast the improvements of the abilities to constrain the cosmological parameters with ET and LISA combined with the Planck.


2020 ◽  
Vol 12 (7) ◽  
pp. 2728
Author(s):  
Ferran Calabuig-Moreno ◽  
María Huertas González-Serrano ◽  
Javier Fombona ◽  
Marta García-Tascón

Technology has been gradually introduced into our society, and the field of education is no exception due to technology’s ability to improve the teaching–learning process. Furthermore, within the area of physical education (PE), its importance has been highlighted by the existence of specific apps for physical activity that can be used inside and outside the classroom to assess physical condition, as well as through the potential that virtual and augmented reality can have in such assessment. Therefore, the main objectives for this study were (1) to perform a bibliometric analysis of the articles published in the Web of Science (WoS) on technology in PE and (2) to analyze the articles published on augmented or virtual reality in PE found through this search. The results show that although studies on technology in PE (461 articles) have begun to consolidate over the last five years (there was a turning point in 2015), with the USA being the most influential country in this area, specific research on the use of augmented reality (AR) and virtual reality (VR) is still at a very early stage (22 articles with a small growth in 2017), with Spain being the most influential country; much more research is needed to achieve its consolidation.


1999 ◽  
Vol 1 (2) ◽  
pp. 101-120 ◽  
Author(s):  
Jeffrey E. Sohl
Keyword(s):  

2018 ◽  
Vol 27 (14) ◽  
pp. 1830009
Author(s):  
Virginia Trimble

A large majority of the physics and astronomy communities are now sure that gravitational waves exist, can be looked for, and can be studied via their effects on laboratory apparatus as well as on astronomical objects. So far, everything found out has agreed with the predictions of general relativity, but hopes are high for new information about the universe and its contents and perhaps for hints of a better theory of gravity than general relativity (which even Einstein expected to come eventually). This is one version of the story, from 1905 to the present, told from an unusual point of view, because the author was, for 28.5 years, married to Joseph Weber, who built the first detectors starting in the early 1960s and operated one or more until his death on 30 September 2000.


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