170,233 research outputs found
MeshfreeFlowNet: A Physics-Constrained Deep Continuous Space-Time Super-Resolution Framework
We propose MeshfreeFlowNet, a novel deep learning-based super-resolution
framework to generate continuous (grid-free) spatio-temporal solutions from the
low-resolution inputs. While being computationally efficient, MeshfreeFlowNet
accurately recovers the fine-scale quantities of interest. MeshfreeFlowNet
allows for: (i) the output to be sampled at all spatio-temporal resolutions,
(ii) a set of Partial Differential Equation (PDE) constraints to be imposed,
and (iii) training on fixed-size inputs on arbitrarily sized spatio-temporal
domains owing to its fully convolutional encoder. We empirically study the
performance of MeshfreeFlowNet on the task of super-resolution of turbulent
flows in the Rayleigh-Benard convection problem. Across a diverse set of
evaluation metrics, we show that MeshfreeFlowNet significantly outperforms
existing baselines. Furthermore, we provide a large scale implementation of
MeshfreeFlowNet and show that it efficiently scales across large clusters,
achieving 96.80% scaling efficiency on up to 128 GPUs and a training time of
less than 4 minutes.Comment: Supplementary Video: https://youtu.be/mjqwPch9gDo. Accepted to SC2
Future Hadron Physics at Fermilab
Today, hadron physics research occurs at Fermilab as parts of broader
experimental programs. This is very likely to be the case in the future. Thus,
much of this presentation focuses on our vision of that future - a future aimed
at making Fermilab the host laboratory for the International Linear Collider
(ILC). Given the uncertainties associated with the ILC - the level of needed
R&D, the ILC costs, and the timing - Fermilab is also preparing for other
program choices. I will describe these latter efforts, efforts focused on a
Proton Driver to increase the numbers of protons available for experiments. As
examples of the hadron physics which will be coming from Fermilab, I summarize
three experiments: MIPP/E907 which is running currently, and MINER A and
Drell-Yan/E906 which are scheduled for future running periods. Hadron physics
coming from the Tevatron Collider program will be summarized by Arthur Maciel
in another talk at Hadron05.Comment: To be published in the Proceedings of the XI International Conference
on Hadron Spectroscopy (Alberto Reis, editor) in the AIP Conference
Proceedings series, 10 page
GRIPS and the Perspective of Next-generation Gamma-ray Surveys
GRIPS is one example of next generation telescopes proposed for astronomy the
energy range between hard X-ray mirror instruments such as NuStar and the Fermi
telescope. The Compton telescope principle is an advantageous concept in view
of background suppression, imaging sensitivity within a large field of view and
energy range, and capability to measure polarization. The diversity of
astrophysical sources at high energies (diffuse emission from cosmic-ray
interactions, nuclear lines from point-like and diffuse sources, accreting
binaries, cosmic-ray acceleration sites, novae and supernovae, GRBs) presents a
challenge, and in particular emphasizes the need for large fields of view and
surveys. We discuss the astrophysical challenges which are expected to remain
after the extended INTEGRAL mission, and how such a next-generation survey at
low-energy gamma-rays would impact on these. We argue that qualitatively new
and more direct insights could be obtained on cosmic high-energy phenomena and
their underlying physical processes.Comment: 7 pages, 2 figures. INTEGRAL Science Worlshop "The Restless Gamma-Ray
Universe", Dublin (IRL) Oct 201
GAME: Grb and All-sky Monitor Experiment
We describe the GRB and All-sky Monitor Experiment (GAME) mission submitted
by a large international collaboration (Italy, Germany, Czech Repubblic,
Slovenia, Brazil) in response to the 2012 ESA call for a small mission
opportunity for a launch in 2017 and presently under further investigation for
subsequent opportunities. The general scientific objective is to perform
measurements of key importance for GRB science and to provide the wide
astrophysical community of an advanced X-ray all-sky monitoring system. The
proposed payload was based on silicon drift detectors (~1-50 keV), CdZnTe (CZT)
detectors (~15-200 keV) and crystal scintillators in phoswich (NaI/CsI)
configuration (~20 keV-20 MeV), three well established technologies, for a
total weight of ~250 kg and a required power of ~240 W. Such instrumentation
allows a unique, unprecedented and very powerful combination of large field of
view (3-4 sr), a broad energy energy band extending from ~1 keV up to ~20 MeV,
an energy resolution as good as ~300 eV in the 1-30 keV energy range, a source
location accuracy of ~1 arcmin. The mission profile included a launch (e.g., by
Vega) into a low Earth orbit, a baseline sky scanning mode plus pointed
observations of regions of particular interest, data transmission to ground via
X-band (4.8 Gb/orbit, Alcantara and Malindi ground stations), and prompt
transmission of GRB / transient triggers.Comment: 13 pages, 8 figures, published in International Journal of Modern
Physics
Space-based research in fundamental physics and quantum technologies
Space-based experiments today can uniquely address important questions
related to the fundamental laws of Nature. In particular, high-accuracy physics
experiments in space can test relativistic gravity and probe the physics beyond
the Standard Model; they can perform direct detection of gravitational waves
and are naturally suited for precision investigations in cosmology and
astroparticle physics. In addition, atomic physics has recently shown
substantial progress in the development of optical clocks and atom
interferometers. If placed in space, these instruments could turn into powerful
high-resolution quantum sensors greatly benefiting fundamental physics.
We discuss the current status of space-based research in fundamental physics,
its discovery potential, and its importance for modern science. We offer a set
of recommendations to be considered by the upcoming National Academy of
Sciences' Decadal Survey in Astronomy and Astrophysics. In our opinion, the
Decadal Survey should include space-based research in fundamental physics as
one of its focus areas. We recommend establishing an Astronomy and Astrophysics
Advisory Committee's interagency ``Fundamental Physics Task Force'' to assess
the status of both ground- and space-based efforts in the field, to identify
the most important objectives, and to suggest the best ways to organize the
work of several federal agencies involved. We also recommend establishing a new
NASA-led interagency program in fundamental physics that will consolidate new
technologies, prepare key instruments for future space missions, and build a
strong scientific and engineering community. Our goal is to expand NASA's
science objectives in space by including ``laboratory research in fundamental
physics'' as an element in agency's ongoing space research efforts.Comment: a white paper, revtex, 27 pages, updated bibliograph
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