Results for "Arazi Pinhas"

total 67took 0.12s
Complete history of the observable 21-cm signal from the first stars during the pre-reionization eraJun 10 2013We present the first complete calculation of the history of the inhomogeneous 21-cm signal from neutral hydrogen during the era of the first stars. We use hybrid computational methods to capture the large-scale distribution of the first stars, whose radiation ... More
Efficiency of Planetesimal Ablation in Giant Planetary EnvelopesSep 07 2016Observations of exoplanetary spectra are leading to unprecedented constraints on their atmospheric elemental abundances, particularly O/H, C/H, and C/O ratios. Recent studies suggest that elemental ratios could provide important constraints on formation ... More
Existence of the $AH+2$ subfactorDec 08 2015We give two different proofs of the existence of the $AH+2$ subfactor, which is a $3$-supertransitive self-dual subfactor with index $\frac{9+\sqrt{17}}{2} $. The first proof is a direct construction using connections on graphs and intertwiner calculus ... More
Retrieval of planetary and stellar properties in transmission spectroscopy with AuraAug 29 2018Transmission spectroscopy provides a powerful probe of the atmospheric properties of transiting exoplanets. To date, studies of exoplanets in transit have focused on inferring their atmospheric properties such as chemical compositions, cloud/haze properties, ... More
Stochastic Wiener Filter in the White Noise SpaceOct 26 2017In this paper we introduce a new approach to the study of filtering theory by allowing to the system's parameters to have uncertainty behavior. We use Hida's white noise space theory to give an alternative characterization to the Wiener filter over the ... More
The Brauer-Picard group of the Asaeda-Haagerup fusion categoriesFeb 20 2012Jan 02 2014We prove that the Brauer-Picard group of Morita autoequiv- alences of each of the three fusion categories which arise as an even part of the Asaeda-Haagerup subfactor or of its index 2 extension is the Klein four-group. We describe the 36 bimodule categories ... More
Quantum doubles of generalized Haagerup subfactors and their orbifoldsJan 30 2015We show how to compute the quantum doubles of generalized Haagerup subfactors for groups of even order and their equivariantizations and de-equivariantizations. We find the modular data for several small-index subfactors, including the Asaeda-Haagerup ... More
Classification of Noncommuting Quadrilaterals of FactorsApr 09 2007Apr 27 2007A quadrilateral of factors is an irreducible inclusion of factors $N \subset M$ with intermediate subfactors $P$ and $Q$ such that $P$ and $Q$ generate $M$ and the intersection of $P$ and $Q$ is $N$. We investigate the structure of a non-commuting quadrilateral ... More
Quantum subgroups of the Haagerup fusion categoriesFeb 13 2011Sep 01 2011We answer three related questions concerning the Haagerup subfactor and its even parts, the Haagerup fusion categories. Namely we find all simple module categories over each of the Haagerup fusion categories (in other words, we find the `"quantum subgroups" ... More
A quadrilateral in the Asaeda-Haagerup categoryJun 13 2010Jun 25 2010We construct a noncommuting quadrilateral of factors whose upper sides are each the Asaeda-Haagerup subfactor with index $\frac{5+\sqrt{17}}{2} $ by showing the existence of a Q-system in the Asaeda-Haagerup category with index $\frac{7+\sqrt{17}}{2} ... More
Strong Singularity for SubfactorsMar 22 2007Oct 23 2008We examine the notion of $\alpha$-strong singularity for subfactors of a \IIi factor, which is a metric quantity that relates the distance between a unitary in the factor and a subalgebra with the distance between that subalgebra and its unitary conjugate. ... More
Some aspects of cylindrical solutions in Brans-Dicke gravityFeb 17 2011Several points regarding cylindrical Brans-Dicke geometries are studied. The issue of particle trajectories for the vacuum cylindrical solution is revisited. The possible particular nature of a global string metric is analysed. The general form of the ... More
Wiggly Strings in Linearized Brans-Dicke GravitySep 21 2000Feb 19 2004The metric around a wiggly cosmic string is calculated in the linear approximation of Brans-Dicke theory of gravitation. The equations of motion for relativistic and non-relativistic particles in this metric are obtained. Light propagation is also studied ... More
Cylindrical sources in full Einstein and Brans-Dicke gravityMay 09 2000It was shown by Hiscock that the energy-momentum tensor commonly used to model local cosmic strings in linearized Einstein gravity can be extended and used in the full theory, obtaining a metric in the exterior of the source with the same deficit angle. ... More
The Asaeda-Haagerup fusion categoriesJan 29 2015The classification of subfactors of small index revealed several new subfactors. The first subfactor above index 4, the Haagerup subfactor, is increasingly well understood and appears to lie in a (discrete) infinite family of subfactors where the Z/3Z ... More
Intermediate Subfactors with No Extra StructureDec 21 2004Feb 14 2005If $N \subset P,Q \subset M$ are type II_1 factors with $N' \cap M = C id$ and $[M:N]$ finite we show that restrictions on the standard invariants of the elementary inclusions $N \subset P$, $N \subset Q$, $P \subset M$ and $Q \subset M$ imply drastic ... More
Constraining Stellar Photospheres as an Essential Step for Transmission Spectroscopy of Small ExoplanetsMar 14 2019Transmission spectra probe the atmospheres of transiting exoplanets, but these observations are also subject to signals introduced by magnetic active regions on host stars. Here we outline scientific opportunities in the next decade for providing useful ... More
de Branges spaces on compact Riemann surfaces and a Beurling-Lax type theoremJun 22 2018Using the notion of commutative operator vessels, this work investigates de Branges-Rovnyak spaces whose elements are multiplicative sections of a line bundle on a real compact Riemann surface. As a special case, we obtain a Beurling-Lax type theorem ... More
Linear State space theory in the white noise space settingNov 13 2009We study state space equations within the white noise space setting. A commutative ring of power series in a countable number of variables plays an important role. Transfer functions are rational functions with coefficients in this commutative ring, and ... More
Commuting operators over Pontryagin spaces with applications to system theoryJun 27 2018In this paper we extend vessel theory, or equivalently, the theory of overdetermined $2D$ systems to the Pontryagin space setting. We focus on realization theorems of the various characteristic functions associated to such vessels. In particular, we develop ... More
Near-optimal sample compression for nearest neighborsApr 13 2014Dec 05 2014We present the first sample compression algorithm for nearest neighbors with non-trivial performance guarantees. We complement these guarantees by demonstrating almost matching hardness lower bounds, which show that our bound is nearly optimal. Our result ... More
Cyclic extensions of fusion categories via the Brauer-Picard groupoidNov 27 2012Apr 11 2013We construct a long exact sequence computing the obstruction space, pi_1(BrPic(C_0)), to G-graded extensions of a fusion category C_0. The other terms in the sequence can be computed directly from the fusion ring of C_0. We apply our result to several ... More
Mimicking Collective Firing Patterns of Hundreds of Connected Neurons using a Single-Neuron ExperimentJan 10 2016The experimental study of neural networks requires simultaneous measurements of a massive number of neurons, while monitoring properties of the connectivity, synaptic strengths and delays. Current technological barriers make such a mission unachievable. ... More
Broadband Macroscopic Cortical Oscillations Emerge from Intrinsic Neuronal Response FailuresNov 01 2015Broadband spontaneous macroscopic neural oscillations are rhythmic cortical firing which were extensively examined during the last century, however, their possible origination is still controversial. In this work we show how macroscopic oscillations emerge ... More
An optical transmission spectrum of the ultra-hot Jupiter WASP-33b. First indication of AlO in an exoplanetNov 06 2018There has been increasing progress toward detailed characterization of exoplanetary atmospheres, in both observations and theoretical methods. Improvements in observational facilities and data reduction and analysis techniques are enabling increasingly ... More
Cavity ring-up spectroscopy for ultrafast sensing with optical microresonatorsJan 07 2015Spectroscopy of whispering-gallery mode (WGM) microresonators has become a powerful scientific tool, enabling detection of single viruses, nanoparticles, and even single molecules. Yet the demonstrated timescale of these schemes has been limited so far ... More
On the potential for reconstructing the moisture field using commercial microwave network dataJun 03 2018The atmospheric greenhouse effect and the hydrological cycle of Earth are key components enabling the planet to support life. Water vapor is a central element in both of these, accounting for approximately half of the present day greenhouse effect, and ... More
Spiking Optical Patterns and SynchronizationJun 11 2007We analyze the time resolved spike statistics of a solitary and two mutually interacting chaotic semiconductor lasers whose chaos is characterized by apparently random, short intensity spikes. Repulsion between two successive spikes is observed, resulting ... More
Synchronization of mutually coupled chaotic lasers in the presence of a shutterOct 15 2006Two mutually coupled chaotic diode lasers exhibit stable isochronal synchronization in the presence of self feedback. When the mutual communication between the lasers is discontinued by a shutter and the two uncoupled lasers are subject to self-feedback ... More
Neuronal Response Impedance Mechanism Implementing Cooperative Networks with Low Firing Rates and Microseconds PrecisionNov 19 2014Jun 01 2015Realizations of low firing rates in neural networks usually require globally balanced distributions among excitatory and inhibitory links, while feasibility of temporal coding is limited by neuronal millisecond precision. We show that cooperation, governing ... More
First studies with the Resistive-Plate WELL gaseous multiplierAug 28 2013We present the results of first studies of the Resistive Plate WELL (RPWELL): a single-faced THGEM coupled to a copper anode via a resistive layer of high bulk resistivity. We explored various materials of different bulk resistivity (10^9 - 10^12 Ohm ... More
Uncertainties of optical-model parameters for the study of the threshold anomalyMar 13 2015In the analysis of elastic-scattering experimental data, optical-model parameters (usually, depths of real and imaginary potentials) are fitted and conclusions are drawn analyzing their variations at bombardment energies close to the Coulomb barrier (threshold ... More
Laboratory studies of THGEM-based WELL structures with resistive anodesOct 23 2013In this work we investigate three variants of single amplification-stage detector elements; they comprise THGEM electrodes closed at their bottom with metallic or resistive anodes to form WELL-type configurations. We present the results of a comparative ... More
Optical readout: a tool for studying gas-avalanche processesMay 06 2013Jan 05 2014Optical recording of avalanche-induced photons is an interesting tool for studying basic physics processes in gaseous detectors. In this work we demonstrate the potential of optical readout in avalanche-propagation investigations in Thick Gas Electron ... More
Direct observation of bubble-assisted electroluminescence in liquid xenonSep 08 2015Bubble formation in liquid xenon underneath a Thick Gaseous Electron Multiplier (THGEM) electrode immersed in liquid xenon was observed with a CCD camera. With voltage across the THGEM, the appearance of bubbles was correlated with that of electroluminescence ... More
A Comprehensive Simulation Study of a Liquid-Xe Detector for Contraband DetectionDec 31 2014Recently, a new detector concept, for combined imaging and spectroscopy of fast-neutrons and gamma was presented. It encompasses a liquid-xenon (LXe) converter-scintillator coupled to a UV-sensitive gaseous Thick Gas Electron Multiplier (THGEM)-based ... More
Recent advances with THGEM detectorsOct 15 2013The Thick Gaseous Electron Multiplier (THGEM) is a simple and robust electrode suitable for large area detectors. In this work the results of extensive comparative studies of the physical properties of different THGEM-based structures are reviewed. The ... More
First demonstration of VUV-photon detection in liquid xenon with THGEM and GEM-based Liquid Hole MultipliersMar 24 2016The bubble-assisted Liquid Hole-Multiplier (LHM) is a recently-introduced detection concept for noble-liquid time projection chambers. In this "local dual-phase" detection element, a gas bubble is supported underneath a perforated electrode (e.g., Thick ... More
A concept for laboratory studies of radiation detectors over a broad dynamic-range: instabilities evaluation in THGEM-structuresNov 02 2013Nov 05 2013A simple methodology for evaluating the dynamic-range of gas avalanche detectors in the laboratory is presented and discussed. It comprises two tools: a charge injector of tunable gain which transfers radiation-induced amplified electron swarms to the ... More
Liquid Hole Multipliers: bubble-assisted electroluminescence in liquid xenonMay 09 2015May 13 2015In this work we discuss the mechanism behind the large electroluminescence signals observed at relatively low electric fields in the holes of a Thick Gas Electron Multiplier (THGEM) electrode immersed in liquid xenon. We present strong evidence that the ... More
ABALONE Photosensors for the IceCube ExperimentSep 30 2018The ABALONE Photosensor Technology (U.S. Pat. 9064678) is a modern, scalable technology specifically invented for cost effective mass production, robustness, and high performance. We present the performance of advanced fused silica ABALONE Photosensors, ... More
First observation of liquid-xenon proportional electroluminescence in THGEM holesOct 15 2013Radiation-induced proportional-electroluminescence UV signals, emitted from the holes of a Thick Gas Electron Multiplier (THGEM) electrode immersed in liquid xenon, were recorded with a PMT for the first time. Significant photon yields were observed using ... More
First results of a large-area cryogenic gaseous photomultiplier coupled to a dual-phase liquid xenon TPCAug 03 2015We discuss recent advances in the development of cryogenic gaseous photomultipliers (GPM), for possible use in dark matter and other rare-event searches using noble-liquid targets. We present results from a 10 cm diameter GPM coupled to a dual-phase liquid ... More
The Resistive-Plate WELL with Argon mixtures - a robust gaseous radiation detectorMar 15 2016A thin single-element THGEM-based, Resistive-Plate WELL (RPWELL) detector was operated with 150 GeV/c muon and pion beams in Ne/(5%CH$_4$), Ar/(5%CH$_4$) and Ar/(7%CO$_2$); signals were recorded with 1 cm$^2$ square pads and SRS/APV25 electronics. Detection ... More
In-beam evaluation of a medium-size Resistive-Plate WELL gaseous particle detectorJul 09 2016Sep 08 2016In-beam evaluation of a fully-equipped medium-size 30$\times$30 cm$^2$ Resistive Plate WELL (RPWELL) detector is presented. It consists here of a single element gas-avalanche multiplier with Semitron ESD225 resistive plate, 1 cm$^2$ readout pads and APV25/SRS ... More
Beam studies of novel THGEM-based potential sampling elements for Digital Hadron CalorimetryMay 20 2013Jul 25 2013Beam studies of thin single- and double-stage THGEM-based detectors are presented. Several 10 x 10 cm^2 configurations with a total thickness of 5-6 mm (excluding readout electronics), with 1 x 1 cm^2 pads inductively coupled through a resistive layer ... More
Comparison of 120Sn(6He,6He)120Sn and 120Sn(alpha,alpha)120Sn elastic scattering and signatures of the 6He neutron halo in the optical potentialSep 24 2010Cross sections of $^{120}$Sn($\alpha$,$\alpha$)$^{120}$Sn elastic scattering have been extracted from the $\alpha$ particle beam contamination of a recent $^{120}$Sn($^6$He,$^6$He)$^{120}$Sn experiment. Both reactions are analyzed using systematic double ... More
Beam Studies of the Segmented Resistive WELL: a Potential Thin Sampling Element for Digital Hadron CalorimetryMay 07 2013Thick Gas Electron Multipliers (THGEMs) have the potential of constituting thin, robust sampling elements in Digital Hadron Calorimetry (DHCAL) in future colliders. We report on recent beam studies of new single- and double-THGEM-like structures; the ... More
First in-beam studies of a Resistive-Plate WELL gaseous multiplierOct 12 2015Jan 20 2016We present the results of the first in-beam studies of a medium size (10$\times$10 cm$^2$) Resistive-Plate WELL (RPWELL): a single-sided THGEM coupled to a pad anode through a resistive layer of high bulk resistivity ($\sim$10$^9 \Omega$cm). The 6.2~mm ... More
Hybrid Multi Micropattern Gaseous Photomultiplier for detection of liquid-xenon scintillationOct 27 2011Gaseous PhotoMultipliers (GPM) are a very promising alternative of vacuum PMTs especially for large-size noble-liquid detectors in the field of Functional Nuclear Medical Imaging and Direct Dark Matter Detection. We present recent characterization results ... More
$^9$Be+$^{120}$Sn scattering at near-barrier energies within a four body modelApr 02 2018Cross sections for elastic and inelastic scattering of the weakly-bound $^9$Be nucleus on a $^{120}$Sn target have been measured at seven bombarding energies around and above the Coulomb barrier. The elastic angular distributions are analyzed with a four-body ... More
Effect of the break-up on the fusion and elastic scattering of weakly bound projectiles on $^{64}$ZnFeb 01 2005We study the behavior of the fusion, break-up, reaction and elastic scattering of different projectiles on $^{64}$Zn, at near and above barrier energies. We present fusion and elastic scattering data with the tightly bound $^{16}$O and the stable weakly ... More
THGEM-based detectors for sampling elements in DHCAL: laboratory and beam evaluationDec 08 2011We report on the results of an extensive R&D program aimed at the evaluation of Thick-Gas Electron Multipliers (THGEM) as potential active elements for Digital Hadron Calorimetry (DHCAL). Results are presented on efficiency, pad multiplicity and discharge ... More
Elastic Scattering and Total Reaction Cross Section for the 6He + 27Al SystemDec 02 2006The elastic scattering of the radioactive halo nucleus 6He on 27Al target was measured at four energies close to the Coulomb barrier using the RIBRAS (Radioactive Ion Beams in Brazil) facility. The Sao Paulo Potential(SPP) was used and its diffuseness ... More
Initial results on energy resolution of the NEXT-White detectorAug 06 2018Oct 15 2018One of the major goals of the NEXT-White (NEW) detector is to demonstrate the energy resolution that an electroluminescent high pressure xenon TPC can achieve for high energy tracks. For this purpose, energy calibrations with 137Cs and 232Th sources have ... More
Helium-Xenon mixtures to improve topological signature in high pressure gas Xenon TPCsOct 16 2017Dec 20 2018Within the framework of xenon-based double beta decay experiments, we propose the possibility to improve the background rejection of an electroluminescent Time Projection Chamber (EL TPC) by reducing the diffusion of the drifting electrons while keeping ... More
Exclusion of Leptophilic Dark Matter Models using XENON100 Electronic Recoil DataJul 28 2015Laboratory experiments searching for galactic dark matter particles scattering off nuclei have so far not been able to establish a discovery. We use data from the XENON100 experiment to search for dark matter interacting with electrons. With no evidence ... More
Measurement of radon-induced backgrounds in the NEXT double beta decay experimentApr 02 2018Oct 10 2018The measurement of the internal $^{222}$Rn activity in the NEXT-White detector during the so-called Run-II period with $^{136}$Xe-depleted xenon is discussed in detail, together with its implications for double beta decay searches in NEXT. The activity ... More
Lowering the radioactivity of the photomultiplier tubes for the XENON1T dark matter experimentMar 26 2015The low-background, VUV-sensitive 3-inch diameter photomultiplier tube R11410 has been developed by Hamamatsu for dark matter direct detection experiments using liquid xenon as the target material. We present the results from the joint effort between ... More
Study of the loss of Xenon Scintillation in Xenon-Trimethylamine MixturesDec 13 2018This work investigates the capability of TMA ((CH3)3N) molecules to shift the wavelength of Xe VUV emission (160-188 nm) to a longer, more manageable, wavelength (260-350 nm). Light emitted from a Xe lamp was passed through a gas chamber filled with Xe-TMA ... More
Electroluminescence TPCs at the thermal diffusion limitJun 15 2018Oct 30 2018The NEXT experiment aims at searching for the hypothetical neutrinoless double-beta decay from the ${}^{136}$Xe isotope using a high-purity xenon TPC. Efficient discrimination of the events through pattern recognition of the topology of primary ionisation ... More
Search for Event Rate Modulation in XENON100 Electronic Recoil DataJul 28 2015We have searched for periodic variations of the electronic recoil event rate in the (2-6) keV energy range recorded between February 2011 and March 2012 with the XENON100 detector, adding up to 224.6 live days in total. Following a detailed study to establish ... More
Calibration of the NEXT-White detector using $^{83m}\mathrm{Kr}$ decaysApr 05 2018Sep 18 2018The NEXT-White (NEW) detector is currently the largest radio-pure high-pressure xenon gas time projection chamber with electroluminescent readout in the world. NEXT-White has been operating at Laboratorio Subterr\'aneo de Canfranc (LSC) since October ... More
The Next White (NEW) detectorApr 06 2018Conceived to host 5 kg of xenon at a pressure of 15 bar in the fiducial volume, the NEXT- White (NEW) apparatus is currently the largest high pressure xenon gas TPC using electroluminescent amplification in the world. It is also a 1:2 scale model of the ... More
Electron drift properties in high pressure gaseous xenonApr 05 2018May 28 2018Gaseous time projection chambers (TPC) are a very attractive detector technology for particle tracking. Characterization of both drift velocity and diffusion is of great importance to correctly assess their tracking capabilities. NEXT-White is a High ... More
DARWIN: towards the ultimate dark matter detectorJun 22 2016DARk matter WImp search with liquid xenoN (DARWIN) will be an experiment for the direct detection of dark matter using a multi-ton liquid xenon time projection chamber at its core. Its primary goal will be to explore the experimentally accessible parameter ... More
Physics reach of the XENON1T dark matter experimentDec 23 2015Apr 15 2016The XENON1T experiment is currently in the commissioning phase at the Laboratori Nazionali del Gran Sasso, Italy. In this article we study the experiment's expected sensitivity to the spin-independent WIMP-nucleon interaction cross section, based on Monte ... More