3,876 research outputs found
Asymptotic safety in three-dimensional SU(2) Group Field Theory: evidence in the local potential approximation
We study the functional renormalization group of a three-dimensional
tensorial Group Field Theory (GFT) with gauge group SU(2). This model generates
(generalized) lattice gauge theory amplitudes, and is known to be
perturbatively renormalizable up to order 6 melonic interactions. We consider a
series of truncations of the exact Wetterich--Morris equation, which retain
increasingly many perturbatively irrelevant melonic interactions. This
tensorial analogue of the ordinary local potential approximation allows to
investigate the existence of non-perturbative fixed points of the
renormalization group flow. Our main finding is a candidate ultraviolet fixed
point, whose qualitative features are reproduced in all the truncations we have
checked (with up to order 12 interactions). This may be taken as evidence for
an ultraviolet completion of this GFT in the sense of asymptotic safety.
Moreover, this fixed point has a single relevant direction, which suggests the
presence of two distinct infrared phases. Our results generally support the
existence of GFT phases of the condensate type, which have recently been
conjectured and applied to quantum cosmology and black holes.Comment: 43 pages, many figures; v2: minor correction
On Determinism and Unambiguity of Weighted Two-way Automata
In this paper, we first study the conversion of weighted two-way automata to
one-way automata. We show that this conversion preserves the unambiguity but
does not preserve the determinism. Yet, we prove that the conversion of an
unambiguous weighted one-way automaton into a two-way automaton leads to a
deterministic two-way automaton. As a consequence, we prove that unambiguous
weighted two-way automata are equivalent to deterministic weighted two-way
automata in commutative semirings.Comment: In Proceedings AFL 2014, arXiv:1405.527
Generating a 3D Simulation of a Car Accident from a Written Description in Natural Language: the CarSim System
This paper describes a prototype system to visualize and animate 3D scenes
from car accident reports, written in French. The problem of generating such a
3D simulation can be divided into two subtasks: the linguistic analysis and the
virtual scene generation. As a means of communication between these two
modules, we first designed a template formalism to represent a written accident
report. The CarSim system first processes written reports, gathers relevant
information, and converts it into a formal description. Then, it creates the
corresponding 3D scene and animates the vehicles.Comment: 8 pages, ACL 2001, Workshop on Temporal and Spatial Information
Processin
The new very small angle neutron scattering spectrometer at Laboratoire Leon Brillouin
The design and characteristics of the new very small angle neutron scattering
spectrometer under construction at the Laboratoire Leon Brillouin is described.
Its goal is to extend the range of scattering vectors magnitudes towards
2x10{-4} /A. The unique feature of this new spectrometer is a high resolution
two dimensional image plate detector sensitive to neutrons. The wavelength
selection is achieved by a double reflection supermirror monochromator and the
collimator uses a novel multibeam design
Analysis of total dose-induced dark current in CMOS image sensors from interface state and trapped charge density measurements
The origin of total ionizing dose induced dark current in CMOS image sensors is investigated by comparing dark current
measurements to interface state density and trapped charge density measurements. Two types of photodiode and several thick-oxide-FETs were manufactured using a 0.18-µm CMOS image sensor process and exposed to 10-keV X-ray from 3 krad to 1 Mrad. It is shown that the radiation induced trapped charge extends the space charge region at the oxide interface, leading to an enhancement of interface state SRH generation current.
Isochronal annealing tests show that STI interface states anneal out at temperature lower than 100°C whereas about a third of the trapped charge remains after 30 min at 300°C
Représenter la diversité : opportunité ou fardeau électoral ?
La question de la représentation des différentes composantes de la société est un vieux serpent de mer de la démocratie française. La sur-représentation des uns et la sur-représentation des autres font l’objet de débats récurrents et polémiques en France depuis la naissance de la République. En accord avec la thématique du complot, l’extrême-droite catholique a, depuis la Révolution française, abordé la question de la représentation en termes confessionnels, dénonçant la marginalisation des catholiques au sein du personnel politique au profit en particulier des confessions juives et protestantes. La représentation et
ses biais ont fait également l’objet d’approches politiques ou sociologiques en termes de classes ou de catégories socioprofessionnelles. La sous-représentation des ouvriers a constitué longtemps l’une des critiques de l’extrême-gauche contre la « République bourgeoise » (...)
Technological and Economical Survey of Organic Rankine Cycle Systems
peer reviewedThis paper presents an overview of current R&D in the field of small and middle scale Organic Rankine Cycles (ORC’s). Major ORC’s applications are described and their technical and economical maturity is analyzed. The paper also emphasizes the selection criteria for the expander and for the working fluid
Synthetic three-dimensional atomic structures assembled atom by atom
We demonstrate the realization of large, fully loaded, arbitrarily-shaped
three-dimensional arrays of single atoms. Using holographic methods and
real-time, atom-by-atom, plane-by-plane assembly, we engineer atomic structures
with up to 72 atoms separated by distances of a few micrometres. Our method
allows for high average filling fractions and the unique possibility to obtain
defect-free arrays with high repetition rates. These results find immediate
application for the quantum simulation of spin Hamiltonians using Rydberg atoms
in state-of-the-art platforms, and are very promising for quantum-information
processing with neutral atoms.Comment: 5 pages, 3 figure
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