cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Golden Probe of Electroweak Symmetry Breaking
Creators: name: Chen, Yi
name: Lykken, Joe
name: Spiropulu, Maria
name: Stolarski, Daniel
name: Vega-Morales, Roberto
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: The ratio of the Higgs couplings to $WW$ and $ZZ$ pairs, $λ_{WZ}$, is a fundamental parameter in electroweak symmetry breaking as well as a measure of the (approximate) custodial symmetry possessed by the gauge boson mass matrix. We show that Higgs decays to four leptons are sensitive, via tree level/1-loop interference effects, to both the magnitude and, in particular, overall sign of $λ_{WZ}$. Determining this sign requires interference effects, as it is nearly impossible to measure with rate information. Furthermore, simply determining the sign effectively establishes the custodial representation of the Higgs boson. We find that $h\to4\ell$ ($4\ell \equiv 2e2μ, 4e, 4μ$) decays have excellent prospects of directly establishing the overall sign at a high luminosity 13 TeV LHC. We also examine the ultimate LHC sensitivity in $h\to4\ell$ to the magnitude of $λ_{WZ}$. Our results are independent of other measurements of the Higgs boson couplings and, in particular, largely free of assumptions about the top quark Yukawa couplings which also enter at 1-loop. This makes $h\to4\ell$ a unique and independent probe of the electroweak symmetry breaking mechanism and custodial symmetry.
description: 8 pages
Spintronics via non-axisymmetric chiral skyrmions
Creators: name: Leonov, A. O.
name: Loudon, J. C.
name: Bogdanov, A. N.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Micromagnetic calculations demonstrate a peculiar evolution of non-axisymmetric skyrmions driven by an applied magnetic field in confined helimagnets with longitudinal modulations. We argue that these specific solitonic states can be employed in nanoelectronic devices as an effective alternative to the common axisymmetric skyrmions which occur in magnetically saturated states.
Thermal and Magnetic Properties of Nanostructured Ferrimagnetic Composites with Graphene - Graphite Fillers
Creators: name: Ramirez, S.
name: Chan, K.
name: Hernandez, R.
name: Recinos, E.
name: Hernandez, E.
name: Salgado, R.
name: Khitun, A. G.
name: Garay, J. E.
name: Balandin, A. A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We report the results of an experimental study of thermal and magnetic properties of nanostructured ferrimagnetic iron oxide composites with graphene and graphite fillers synthesized via the current activated pressure assisted densification. The thermal conductivity was measured using the laser-flash and transient plane source techniques. It was demonstrated that addition of 5 wt. % of equal mixture of graphene and graphite flakes to the composite results in a factor of x2.6 enhancement of the thermal conductivity without significant degradation of the saturation magnetization. The microscopy and spectroscopic characterization reveal that sp2 carbon fillers preserve their crystal structure and morphology during the composite processing. The strong increase in the thermal conductivity was attributed to the excellent phonon heat conduction properties of graphene and graphite. The results are important for energy and electronic applications of the nanostructured permanent magnets.
description: 22 pages, 5 figures
On Rank Two Toda System with Arbitrary Singularities: Local Mass and New Estimates
Creators: name: Lin, Changshou
name: Wei, Juncheng
name: Yang, Wen
name: Zhang, Lei
Publisher: name: arXiv
Year: 2016
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: 35J60, 35J55

description: For all rank two Toda systems with an arbitrary singular source, we use a unified approach to prove: (i) The pair of local masses $(σ_1,σ_2)$ at each blowup point has the expression $$σ_i=2(N_{i1}μ_1+N_{i2}μ_2+N_{i3}),$$ where $N_{ij}\in\mathbb{Z},~i=1,2,~j=1,2,3.$ (ii) Suppose at each vortex point $p_t$, $(α_1^t,α_2^t)$ are integers and $ρ_i\notin 4π\mathbb{N}$, then all the solutions of Toda systems are uniformly bounded. (iii) If the blow up point $q$ is not a vortex point, then $$u^k(x)+2\log|x-x^k|\leq C,$$ where $x^k$ is the local maximum point of $u^k$ near $q$. (iv) If the blow up point $q$ is a vortex point $p_t$ and $α_t^1,α_t^2$ and $1$ are linearly independent over $Q$, then $$u^k(x)+2\log|x-p_t|\leq C.$$ The Harnack type inequalities of (iii) or (iv) is important for studying the bubbling behaves near each blow up point.
description: 26 pages
Learning many-body Hamiltonians with Heisenberg-limited scaling
Creators: name: Huang, Hsin-Yuan
name: Tong, Yu
name: Fang, Di
name: Su, Yuan
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: Information Theory (cs.IT)
subject: Machine Learning (cs.LG)
subject: Numerical Analysis (math.NA)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: Learning a many-body Hamiltonian from its dynamics is a fundamental problem in physics. In this work, we propose the first algorithm to achieve the Heisenberg limit for learning an interacting $N$-qubit local Hamiltonian. After a total evolution time of $\mathcal{O}(ε^{-1})$, the proposed algorithm can efficiently estimate any parameter in the $N$-qubit Hamiltonian to $ε$-error with high probability. The proposed algorithm is robust against state preparation and measurement error, does not require eigenstates or thermal states, and only uses $\mathrm{polylog}(ε^{-1})$ experiments. In contrast, the best previous algorithms, such as recent works using gradient-based optimization or polynomial interpolation, require a total evolution time of $\mathcal{O}(ε^{-2})$ and $\mathcal{O}(ε^{-2})$ experiments. Our algorithm uses ideas from quantum simulation to decouple the unknown $N$-qubit Hamiltonian $H$ into noninteracting patches, and learns $H$ using a quantum-enhanced divide-and-conquer approach. We prove a matching lower bound to establish the asymptotic optimality of our algorithm.
description: 11 pages, 1 figure + 27-page appendix
The inverse problem beyond two-body interaction: the cubic mean-field Ising model
Creators: name: Contucci, Pierluigi
name: Osabutey, Godwin
name: Vernia, Cecilia
Publisher: name: arXiv
Year: 2022
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: In this paper we solve the inverse problem for the cubic mean-field Ising model. Starting from configuration data generated according to the distribution of the model we reconstruct the free parameters of the system. We test the robustness of this inversion procedure both in the region of uniqueness of the solutions and in the region where multiple thermodynamics phases are present.
Ultrafast reversible self-assembly of living tangled matter
Creators: name: Patil, Vishal P.
name: Tuazon, Harry
name: Kaufman, Emily
name: Chakrabortty, Tuhin
name: Qin, David
name: Dunkel, Jörn
name: Bhamla, M. Saad
Publisher: name: arXiv
Year: 2022
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: Tangled active filaments are ubiquitous in nature, from chromosomal DNA and cilia carpets to root networks and worm blobs. How activity and elasticity facilitate collective topological transformations in living tangled matter is not well understood. Here, we report an experimental and theoretical study of California blackworms (Lumbriculus variegatus), which slowly form tangles over minutes but can untangle in milliseconds. Combining ultrasound imaging, theoretical analysis and simulations, we develop and validate a mechanistic model that explains how the kinematics of individual active filaments determines their emergent collective topological dynamics. The model reveals that resonantly alternating helical waves enable both tangle formation and ultrafast untangling. By identifying generic dynamical principles of topological self-transformations, our results can provide guidance for designing new classes of topologically tunable active materials.
Infrared Observations of the Quintuplet Proper Members using SOFIA/FORCAST and Gemini/TReCS
Creators: name: Hankins, Matthew J.
name: Lau, Ryan M.
name: Morris, Mark R.
name: Sanchez-Bermudez, Joel
name: Pott, Jörg-Uwe
name: Adams, Joseph D.
name: Herter, Terry L.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Since their discovery, the Quintuplet proper members (QPMs) have been somewhat mysterious in nature. Originally dubbed the "cocoon stars" due to their cool featureless spectra, high-resolution near-infrared imaging observations have shown that at least two of the objects exhibit "pinwheel" nebulae consistent with binary systems with a carbon-rich Wolf-Rayet star and O/B companion. In this paper, we present 19.7, 25.2, 31.5, and 37.1 $μ$m observations of the QPMs (with an angular resolution of 3.2-3.8") taken with the Faint Object Infrared Camera for the SOFIA Telescope (FORCAST) in conjunction with high-resolution ($\sim$0.1-0.2") images at 8.8 and 11.7 $μ$m from the Thermal-Region Camera Spectrograph (TReCS). DUSTY models of the thermal dust emission of two of the four detected QPMs, Q2 and Q3, are fitted by radial density profiles which are consistent with constant mass loss rates ($ρ_d \propto r^{-2}$). For the two remaining sources, Q1 and Q9, extended structures ($\sim$ 1") are detected around these objects in high-resolution imaging data. Based on the fitted dust masses, Q9 has an unusually large dust reservoir ($\mathrm{M_d}=1.3^{+0.8}_{-0.4}\times 10^{-3} \mathrm{M_{\odot}}$) compared to typical dusty Wolf-Rayet stars which suggests that it may have recently undergone an episode of enhanced mass loss.
description: 28 pages, 10 figures. Accepted to ApJ
Youth, media and public discourse during the pandemic in Chile
Creators: name: Brossi, Lionel
name: Ibáñez Canelo, María Jesús
name: Hoffmann, Tamara
name: Castillo, Ana María
name: Cortesi, Sandra
Publisher: name: HCIAS Working Papers on Ibero-America
Year: 2022

description: This paper explores how media and public discourse around youth and COVID-19 intersect with the attitude and wellbeing of young people. The qualitative methodology used for this study consisted in an online workshop that involved 4 focus groups and a socio-demographic survey with 13 teenagers between 13 and 17 years old from different areas and contexts in Chile, including their daily routines and experiences during the pandemic. Results show that youth reported being affected by media and public discourses in their daily lives during the sanitary crisis, and perceived to be stigmatized, instrumentalized and invisibilized in terms of their agency, abilities and ethics of care to cope with the COVID-19 pandemic.
description: HCIAS Working Papers on Ibero-America, HCIAS Working Papers on Ibero-America, Volume I (2022)
Universality class of the mode-locked glassy random laser
Creators: name: Niedda, Jacopo
name: Gradenigo, Giacomo
name: Leuzzi, Luca
name: Parisi, Giorgio
Publisher: name: arXiv
Year: 2022
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: By means of enhanced Monte Carlo numerical simulations parallelized on GPU's we study the critical properties of the spin-glass-like model for the mode-locked glassy random laser, a $4$-spin model with complex spins with a global spherical constraint and quenched random interactions. Using two different boundary conditions for the mode frequencies we identify the critical points and the critical indices of the random lasing phase transition using , with finite size scaling techniques. The outcome of the scaling analysis is that the mode-locked random laser is in a mean-field universality class, though different from the mean-field class of the Random Energy Model and the glassy random laser in the narrow band approximation, that is, the fully connected version of the present model. The low temperature (high pumping) phase is finally characterized by means of the overlap distribution and evidence for the onset of replica symmetry breaking in the lasing regime is provided.
description: 17 pages, 11 figures
Feynman integral reduction using Gröbner bases
Creators: name: Barakat, Mohamed
name: Brüser, Robin
name: Fieker, Claus
name: Huber, Tobias
name: Piclum, Jan
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences
subject: 13P10, 16D25, 16Z05, 81Q30, 81T18

description: We investigate the reduction of Feynman integrals to master integrals using Gröbner bases in a rational double-shift algebra Y in which the integration-by-parts (IBP) relations form a left ideal. The problem of reducing a given family of integrals to master integrals can then be solved once and for all by computing the Gröbner basis of the left ideal formed by the IBP relations. We demonstrate this explicitly for several examples. We introduce so-called first-order normal-form IBP relations which we obtain by reducing the shift operators in Y modulo the Gröbner basis of the left ideal of IBP relations. For more complicated cases, where the Gröbner basis is computationally expensive, we develop an ansatz based on linear algebra over a function field to obtain the normal-form IBP relations.
description: 25 pages, 4 figures, 12 ancillary files; v2: clarified text and improved notation
Chandra Observes the End of an Era SN 1987A
Creators: name: Frank, Kari A.
name: Zhekov, Svetozar A.
name: Park, Sangwook
name: McCray, Richard
name: Dwek, Eli
name: Burrows, David N.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Updated imaging and photometric results from Chandra observations of SN 1987A, covering the last 16 years, are presented. We find that the 0.5-2 keV light curve has remained constant at ~8x10^-12 erg s^-1 cm^-2 since 9500 days, with the 3-8 keV light curve continuing to increase until at least 10000 days. The expansion rate of the ring is found to be energy dependent, such that after day 6000 the ring expands faster in the 2-10 keV band than it does at energies <2 keV. Images show a reversal of the east-west asymmetry between 7000 and 8000 days after the explosion. The latest images suggest the southeastern side of the equatorial ring is beginning to fade. Consistent with the latest optical and infrared results, our Chandra analysis indicates the blast wave is now leaving the dense equatorial ring, which marks the beginning of a major change in the evolutionary phase of the supernova remnant 1987A.
Ultrafast non-equilibrium dynamics of rotons in superfluid helium
Creators: name: Milner, A. A.
name: Stamp, P. C. E.
name: Milner, V.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Superfluid 4He, the first superfluid ever discovered, is in some ways the least well understood. Unlike 3He superfluid, or the variety of Bose-Einstein condensates of ultracold gases, superfluid 4He is a very dense liquid of strongly interacting quasiparticles. The theory is then necessarily phenomenological: the quasiparticle properties are found from experiment, and controversies over their description still remain, notably regarding vortex dynamics and the nature of rotons and roton pair creation. It is therefore important to develop new experimental tools for probing the system far from equilibrium. Here we describe a method for locally perturbing the density of superfluid helium through the excitation of roton pairs with ultrashort laser pulses. By measuring the time dependence of this perturbation, we track the non-equilibrium evolution of the two-roton states on a picosecond timescale. Our results reveal an ultrafast cooling of hot roton pairs as they thermalize with the colder gas of other quasiparticles. We anticipate that these findings, as well as future applications of the introduced ultrafast laser technique to different temperature and pressure regimes in bulk liquid 4He, will stimulate further experimental and theoretical investigations towards better understanding of superfluidity.
MPEC 2023-N15 : COMET P/2023 M2 (PANSTARRS)
Creators: name: Minor Planet Center Staff
Publisher: name: The Minor Planet Center
Year: 2023
Subjects: subject: Small Solar System bodies
valueUri: http://astrothesaurus.org/uat/1469
subject: COMET P/2023 M2 (PANSTARRS)

description: The Minor Planet Electronic Circulars contain information on unusual minor planets, routine data on comets and natural satellites, and occasional editorial announcements.  They are published on behalf of Division F of the International Astronomical Union by the Minor Planet Center, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Searching for compact objects in the single-lined spectroscopic binaries of the young Galactic cluster NGC 6231
Creators: name: Banyard, G.
name: Mahy, L.
name: Sana, H.
name: Bodensteiner, J.
name: Villaseńor, J. I.
name: Sen, K.
name: Langer, N.
name: de Mink, S.
name: Picco, A.
name: Shenar, T.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Recent evolutionary computations predict that a few percent of massive OB stars in binary systems should have a dormant BH companion. Despite several reported X-ray quiet OB+BH systems over the last couple of years, finding them with certainty remains challenging. These have great importance as they can be gravitational wave (GW) source progenitors, and are landmark systems in constraining supernova kick physics. This work aims to characterise the hidden companions to the single-lined spectroscopic binaries (SB1s) in the B star population of the young open Galactic cluster NGC 6231 to find candidate systems for harbouring compact object companions. With the orbital solutions for each SB1 previously constrained, we applied Fourier spectral disentangling to multi-epoch optical VLT/FLAMES spectra of each target to extract a potential signature of a faint companion, and to identify newly disentangled double-lined spectroscopic binaries (SB2s). For targets where the disentangling does not reveal any signature of a stellar companion, we performed atmospheric and evolutionary modelling on the primary to obtain constraints on the unseen companion. Seven newly classified SB2 systems with mass ratios down to near 0.1 were identified. From the remaining targets, for which no faint companion could be extracted from the spectra, four are found to have companion masses in the predicted mass ranges of neutron stars (NSes) and BHes. Two of these have companion masses between 1 and 3.5 $M_{\odot}$, making them potential hosts of NSes (or lower mass main sequence stars). The other two are between 2.5 to 8 $M_{\odot}$ and 1.6 and 26 $M_{\odot}$, respectively, and so are identified as candidates for harbouring BH companions. However, unambiguous identification of these systems as X-ray quiet compact object harbouring binaries requires follow up observations.
description: Submitted to A&A
More Ingredients for an Altarelli Cocktail at MiniBooNE
Creators: name: Kelly, Kevin J.
name: Kopp, Joachim
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: The MiniBooNE excess persists as a significant puzzle in particle physics. Given that the MiniBooNE detector cannot discriminate between electron-like signals and backgrounds due to photons, the goal of this work is to study photon backgrounds in MiniBooNE in depth. We first consider a novel single-photon background arising from multi-nucleon scattering with coherently enhanced initial or final state radiation. This class of processes, which we dub "2p2h$γ$" (two-particle--two-hole + photon) can explain ${\sim}40$ of the ${\sim}560$ excess events observed by MiniBooNE in neutrino mode. Second, we consider the background from neutral-current single-$π^0$ production, where two photons from $π^0\toγγ$ decay are mis-identified as an electron-like shower. We construct a phenomenological likelihood that reproduces MiniBooNE's $π^0\toγγ$ background faithfully. Even with data-driven background estimation techniques, we find there is a residual dependence on the Monte Carlo generator used. Our results motivate a reduction in the significance of the MiniBooNE excess by $0.4σ$.
description: v2: revised the discussion of Monte Carlo statistics, with result now in better agreement with MiniBooNE's, and leaving the anomaly largely intact. Matches version accepted by JHEP
Characterization of elastic topological states using dynamic mode decomposition
Creators: name: Li, Shuaifeng
name: Kevrekidis, Panayotis G.
name: Yang, Jinkyu
Publisher: name: arXiv
Year: 2022
Subjects: subject: Applied Physics (physics.app-ph)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: FOS: Physical sciences

description: Elastic topological states have been receiving increased intention in numerous scientific and engineering fields due to their defect-immune nature, resulting in applications of vibration control and information processing. Here, we present the data-driven discovery of elastic topological states using dynamic mode decomposition (DMD). The DMD spectrum and DMD modes are retrieved from the propagation of the relevant states along the topological boundary, where their nature is learned by DMD. Applications such as classification and prediction can be achieved by the underlying characteristics from DMD. We demonstrate the classification between topological and traditional metamaterials using DMD modes. Moreover, the model enabled by the DMD modes realizes the prediction of topological state propagation along the given interface. Our approach to characterizing topological states using DMD can pave the way towards data-driven discovery of topological phenomena in material physics and more broadly lattice systems.
description: 32 pages, 10 figures
Revisiting the optical $PT$-symmetric dimer
Creators: name: Morales, J. D. Huerta
name: Guerrero, J.
name: López-Aguayo, S.
name: Rodríguez-Lara, B. M.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Optics (physics.optics)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Optics has proved a fertile ground for the experimental simulation of quantum mechanics. Most recently, optical realizations of $\mathcal{PT}$-symmetric quantum mechanics have been shown, both theoretically and experimentally, opening the door to international efforts aiming at the design of practical optical devices exploiting this symmetry. Here, we focus on the optical $\mathcal{PT}$-symmetric dimer, a two-waveguide coupler were the materials show symmetric effective gain and loss, and provide a review of the linear and nonlinear optical realizations from a symmetry based point of view. We go beyond a simple review of the literature and show that the dimer is just the smallest of a class of planar $N$-waveguide couplers that are the optical realization of Lorentz group in 2+1 dimensions. Furthermore, we provide a formulation to describe light propagation through waveguide couplers described by non-Hermitian mode coupling matrices based on a non-Hermitian generalization of Ehrenfest theorem.
description: 25 pages, 12 figures
Joint distributions of partial and global maxima of a Brownian Bridge
Creators: name: Benichou, O.
name: Krapivsky, P. L.
name: Mejia-Monasterio, C.
name: Oshanin, G.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Probability (math.PR)
subject: Statistics Theory (math.ST)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We analyze the joint distributions and temporal correlations between the partial maximum $m$ and the global maximum $M$ achieved by a Brownian Bridge on the subinterval $[0,t_1]$ and on the entire interval $[0,t]$, respectively. We determine three probability distribution functions: The joint distribution $P(m,M)$ of both maxima; the distribution $P(m)$ of the partial maximum; and the distribution $Π(G)$ of the gap between the maxima, $G = M-m$. We present exact results for the moments of these distributions and quantify the temporal correlations between $m$ and $M$ by calculating the Pearson correlation coefficient.
description: 13 pages, 7 figures
Multi-Neutrino Entanglement and Correlations in Dense Neutrino Systems
Creators: name: Illa, Marc
name: Savage, Martin J.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Nuclear Theory (nucl-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The time-evolution of multi-neutrino entanglement and correlations are studied in two-flavor collective neutrino oscillations, relevant for dense neutrino environments, building upon previous works. Specifically, simulations performed of systems with up to 12 neutrinos using Quantinuum's H1-1 20 qubit trapped-ion quantum computer are used to compute n-tangles, and two- and three-body correlations, probing beyond mean-field descriptions. n-tangle re-scalings are found to converge for large system sizes, signaling the presence of genuine multi-neutrino entanglement.
description: 7 pages + 10 pages of Supplementary Material, 9 figures and 11 tables; modified Sec 3; Published version
Tunable spin-orbit coupled Bose-Einstein condensates in deep optical lattices
Creators: name: Salerno, M.
name: Abdullaev, F. Kh.
name: Gammal, A.
name: Tomio, Lauro
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: Binary mixtures of Bose-Einstein condensates trapped in deep optical lattices and subjected to equal contributions of Rashba and Dresselhaus spin-orbit coupling (SOC), are investigated in the presence of a periodic time modulation of the Zeeman field. SOC tunability is explicitly demonstrated by adopting a mean-field tight-binding model for the BEC mixture and by performing an averaging approach in the strong modulation limit. In this case, the system can be reduced to an unmodulated vector discrete nonlinear Schrödinger equation with a rescaled SOC tunning parameter $α$, which depends only on the ratio between amplitude and frequency of the applied Zeeman field. The dependence of the spectrum of the linear system on $α$ has been analytically characterized. In particular, we show that extremal curves (ground and highest excited states) of the linear spectrum are continuous piecewise functions (together with their derivatives) of $α$, which consist of a finite number of decreasing band lobes joined by constant lines. This structure also remains in presence of not too large nonlinearities. Most important, the interactions introduce a number of localized states in the band-gaps that undergo change of properties as they collide with band lobes. The stability of ground states in the presence of the modulating field has been demonstrated by real time evolutions of the original (un-averaged) system. Localization properties of the ground state induced by the SOC tuning, and a parameter design for possible experimental observation have also been discussed.
description: 11 pages, 9 figures
title: Image Registration Using Conformal Log Polar Mapping
Creators: name: Vadapally, Bala Krishna
Publisher: name: Old Dominion University
publisherIdentifier: https://ror.org/04zjtrb98
publisherIdentifierScheme: ROR
Year: 2009

description: Image Registration is the process of aligning, or overlaying two images of the same scene that were taken at different times and/or from different viewing angles and/or by sensors with different modalities or resolutions. The variations in the imaging environment induce the difference between the images of the same scene. In our situation, we have two images of the same scene taken with two sensors, one in the visible and the other in the infrared (IR) domain. The cameras are placed adjacent to each other on a stable platform, and the images are captured almost simultaneously. This means that the only variation we are dealing with is the sensor modality, and not variations in spatial and temporal coordinates. Using image registration we project the visible image into the IR image to rectify both images to the same co-ordinate system. This is done to match the sensor outputs and then produce an information product from the two sensors, which can be used to further analyze and assess the scene. In this thesis we use the conformal log polar mapping (CLPM) for image registration.

The CLPM is invariant to changes in image size, rotation and scale: images of different sizes are mapped to the same CLPM space, rotational changes map to a shift along one of the axes and scale changes a shift long the other. Thus the CLPM for any two images that differ only in rotational and scale changes should be the same. The amount of shift can be used to determine the angle of rotation and the change in scale with respect to the original image. The computed parameters can be used for rectifying the reference image to the original image or vice-versa. In this thesis, a robust approach for image registration is presented, that uses CLPM shifts to compute the parameters representing rotation and scale change, and registers a pair of images. An application of this approach is in multi-sensor fusion that provides illumination-independent surveillance capabilities for day/ night operations.
The disturbance of a millisecond pulsar magnetosphere
Creators: name: Shannon, R. M.
name: Lentati, L. T.
name: Kerr, M.
name: Bailes, M.
name: Bhat, N. D. R.
name: Coles, W. A.
name: Dai, S.
name: Dempsey, J.
name: Hobbs, G.
name: Keith, M. J.
name: Lasky, P. D.
name: Levin, Y.
name: Manchester, R. N.
name: Oslowski, S.
name: Ravi, V.
name: Reardon, D. J.
name: Rosado, P. A.
name: Spiewak, R.
name: van Straten, W.
name: Toomey, L.
name: Wang, J. -B.
name: Wen, L.
name: You, X. -P.
name: Zhu, X. -J.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Pulsar timing has enabled some of the strongest tests of fundamental physics. Central to the technique is the assumption that the detected radio pulses can be used to accurately measure the rotation of the pulsar. Here we report on a broad-band variation in the pulse profile of the millisecond pulsar J1643-1224. A new component of emission suddenly appears in the pulse profile, decays over 4 months, and results in a permanently modified pulse shape. Profile variations such as these may be the origin of timing noise observed in other millisecond pulsars. The sensitivity of pulsar-timing observations to gravitational radiation can be increased by accounting for this variability.
description: Accepted to ApJ Letters
Heat transport in Rayleigh-Benard convection and angular momentum transport in Taylor-Couette flow: a comparative study
Creators: name: Brauckmann, Hannes
name: Eckhardt, Bruno
name: Schumacher, Joerg
Publisher: name: arXiv
Year: 2016
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Rayleigh-Benard convection and Taylor-Couette flow are two canonical flows that have many properties in common. We here compare the two flows in detail for parameter values where the Nusselt numbers, i.e. the thermal transport and the angular momentum transport normalized by the corresponding laminar values, coincide. We study turbulent Rayleigh-Benard convection in air at Rayleigh number Ra=1e7 and Taylor-Couette flow at shear Reynolds number Re_S=2e4 for two different mean rotation rates but the same Nusselt numbers. For individual pairwise related fields and convective currents, we compare the probability density functions normalized by the corresponding root mean square values and taken at different distances from the wall. We find one rotation number for which there is very good agreement between the mean profiles of the two corresponding quantities temperature and angular momentum. Similarly, there is good agreement between the fluctuations in temperature and velocity components. For the heat and angular momentum currents, there are differences in the fluctuations outside the boundary layers that increase with overall rotation and can be related to differences in the flow structures in the boundary layer and in the bulk. The study extends the similarities between the two flows from global quantities to local quantities and reveals the effects of rotation on the transport.
description: accepted for Philosophical Transactions of the Royal Society
Hyper-differential sensitivity analysis with respect to model discrepancy: Optimal solution updating
Creators: name: Hart, Joseph
name: Waanders, Bart van Bloemen
Publisher: name: arXiv
Year: 2022
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics

description: A common goal throughout science and engineering is to solve optimization problems constrained by computational models. However, in many cases a high-fidelity numerical emulation of systems cannot be optimized due to code complexity and computational costs which prohibit the use of intrusive and many query algorithms. Rather, lower-fidelity models are constructed to enable intrusive algorithms for large-scale optimization. As a result of the discrepancy between high and low-fidelity models, optimal solutions determined using low-fidelity models are frequently far from true optimality. In this article we introduce a novel approach that uses post-optimality sensitivities with respect to model discrepancy to update the optimization solution. Limited high-fidelity data is used to calibrate the model discrepancy in a Bayesian framework which in turn is propagated through post-optimality sensitivities of the low-fidelity optimization problem. Our formulation exploits structure in the post-optimality sensitivity operator to achieve computational scalability. Numerical results demonstrate how an optimal solution computed using a low-fidelity model may be significantly improved with limited evaluations of a high-fidelity model.
Long time behaviour of the solution of Maxwell's equations in dissipative generalized Lorentz materials (I) A frequency dependent Lyapunov function approach
Creators: name: Cassier, Maxence
name: Joly, Patrick
name: Martínez, Luis Alejandro Rosas
Publisher: name: arXiv
Year: 2022
Subjects: subject: Analysis of PDEs (math.AP)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 35Q60

description: It is well-known that electromagnetic dispersive structures such as metamaterials can be modelled by generalized Drude-Lorentz models. The present paper is the first of two articles dedicated to dissipative generalized Drude-Lorentz open structures. We wish to quantify the loss in such media in terms of the long time decay rate of the electromagnetic energy for the corresponding Cauchy problem. By using an approach based on frequency dependent Lyapounov estimates, we show that this decay is polynomial in time. These results extend to an unbounded structure the ones obtained for bounded media in [18] via a quite different method based on the notion of cumulated past history and semi-group theory. A great advantage of the approach developed here is to be less abstract and directly connected to the physics of the system via energy balances.
description: 33 pages, 1 figure
Isometry invariance of exact correlation functions in various charts of Minkowski and de Sitter spaces
Creators: name: Akhmedov, E. T.
name: Kochergin, I. V.
name: Milovanova, M. N.
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We consider quantum field theory with selfinteractions in various patches of Minkowski and de Sitter space-times. Namely, in Minkowski space-time we consider separately right (left) Rindler wedge, past wedge and future wedge. In de Sitter space-time we consider expanding Poincare patch, static patch, contracting Poincare patch and global de Sitter itself. In all cases we restrict our considerations to the isometry invariant states leading to maximally analytic propagators. We prove that loop corrections in right (left) Rindler wedge, in the past wedge (of Minkowski space-time), in the static patch and in the expanding Poincare patch (of de Sitter space-time) respect the corresponding isometries of the corresponding symmetric space-times. All these facts are related to the causality and analyticity properties of the propagators for the states that we consider. At the same time in the future wedge, in the contracting Poincare patch and in global de Sitter space-time infrared effects violate the isometries.
description: 35 pages, 6 figures Additional references and minor clarifications added; version accepted to PRD
SMEFT effects on gravitational wave spectrum from electroweak phase transition
Creators: name: Hashino, Katsuya
name: Ueda, Daiki
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Experiment (hep-ex)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Future gravitational wave observations are potentially sensitive to new physics corrections to the Higgs potential once the first-order electroweak phase transition arises. We study the SMEFT dimension-six operator effects on the Higgs potential, where three types of effects are taken into account: (i) SMEFT tree level effect on $φ^6$ operator, (ii) SMEFT tree level effect on the wave function renormalization of the Higgs field, and (iii) SMEFT top-quark one-loop level effect. The sensitivity of future gravitational wave observations to these effects is numerically calculated by performing a Fisher matrix analysis. We find that the future gravitational wave observations can be sensitive to (ii) and (iii) once the first-order electroweak phase transition arises from (i). The dimension-eight $φ^8$ operator effects on the first-order electroweak phase transition are also discussed. The sensitivities of the future gravitational wave observations are also compared with those of future collider experiments.
description: 32 pages, 16 figures; section 6 was added for more explanations
Volume-to-Area Law Entanglement Transition in a non-Hermitian Free Fermionic Chain
Creators: name: Gal, Youenn Le
name: Turkeshi, Xhek
name: Schirò, Marco
Publisher: name: arXiv
Year: 2022
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We consider the dynamics of the non-Hermitian Su-Schrieffer-Heeger model arising as the no-click limit of a continuously monitored free fermion chain where particles and holes are measured on two sublattices. The model has $\mathcal{PT}$-symmetry, which we show to spontaneously break as a function of the strength of measurement backaction, resulting in a spectral transition where quasiparticles acquire a finite lifetime in patches of the Brillouin zone. We compute the entanglement entropy's dynamics in the thermodynamic limit and demonstrate an entanglement transition between volume-law and area-law scaling, which we characterize analytically. Interestingly we show that the entanglement transition and the $\mathcal{PT}$-symmetry breaking do not coincide, the former occurring when the entire decay spectrum of the quasiparticle becomes gapped.
description: version 3 , 4 figures, footnote
Landau Theory and the Emergence of Chirality in Viral Capsids
Creators: name: Dharmavaram, Sanjay
name: Xie, Fangming
name: Klug, William
name: Rudnick, Joseph
name: Bruinsma, Robijn
Publisher: name: arXiv
Year: 2016
Subjects: subject: Biological Physics (physics.bio-ph)
subject: Soft Condensed Matter (cond-mat.soft)
subject: Subcellular Processes (q-bio.SC)
subject: FOS: Physical sciences
subject: FOS: Biological sciences

description: We present a generalized Landau-Brazovskii theory for the solidification of chiral molecules on a spherical surface. With increasing sphere radius one encounters first intervals where robust achiral density modulations appear with icosahedral symmetry via first-order transitions. Next, one en- counters intervals where fragile but stable icosahedral structures still can be constructed but only by superposition of multiple irreducible representations. Chiral icoshedral structures appear via continuous or very weakly first-order transitions. Outside these parameter intervals, icosahedral symmetry is broken along a three-fold axis or a five-fold axis. The predictions of the theory are compared with recent numerical simulations.
Parallel and Perpendicular Alignments of Velocity Gradient and Magnetic Field observed in the Molecular Clouds L1478 and L1482
Creators: name: Schmaltz, Tyler
name: Hu, Yue
name: Lazarian, Alex
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Star formation is a complex process that typically occurs in dense regions of molecular clouds mainly regulated by magnetic fields, magnetohydrodynamic (MHD) turbulence, and self-gravity. However, it remains a challenging endeavor to trace the magnetic field and determine regions of gravitational collapse where the star is forming. Based on the anisotropic properties of MHD turbulence, a new technique termed Velocity Gradient Technique (VGT) has been proposed to address these challenges. In this study, we apply the VGT to two regions of the giant California Molecular Cloud (CMC), namely, L1478 and L1482, and analyze the difference in their physical properties. We use the $^{12}$CO (J = 2 - 1), $^{13}$CO (J = 2 - 1), and C$^{18}$O (J = 2 - 1) emission lines observed with the Heinrich Hertz Submillimeter Telescope. We compare VGT results calculated in the resolutions of $3.3'$ and $10'$ to Planck polarization at 353 GHz and $10'$ to determine areas of MHD turbulence dominance and self-gravity dominance. We show that the resolution difference can introduce misalignment between the two measurements. We find the VGT-measured magnetic fields globally agree with that from Planck in L1478 suggesting self-gravity's effect is insignificant. The best agreement appears in VGT-$^{12}$CO. As for L1482, the VGT measurements are statistically perpendicular to the Planck polarization indicating the dominance of self-gravity. This perpendicular alignment is more significant in VGT-$^{13}$CO and VGT-C$^{18}$O.
description: 14 pages, 16 figures, accepted for publication in MNRAS
The Art of Asking Questions: Adopting Critical-Design Thinking in the Digitalisation of Solutions
Creators: name: Patel, Nadya Shaznay
name: Teo, Shan Chian
Publisher: name: Singapore Institute of Technology
Year: 2022
Subjects: Sustainable design
Design practice and methods
Humanities and social sciences curriculum and pedagogy (excl. economics, business and management)
Food sustainability

description: The problems we increasingly face require a radically different form of thinking - one that would rigorously question ideas and assumptions. The new world facing us demands skillful thinkers to come up with new ways of living and new solutions to world’s greatest problems. Of late, these include utilizing a design innovation approach, which arguably cannot take place in the absence of critical thinking. It is thus crucial to integrate critical and design thinking when innovating for solutions. After all, it is bad design if every and any digital tool is assumed to be capable of meaningfully resolving real world, often multifaceted problems. Adopting a critical-design thinking conceptual model, this interactive 1.5-hour workshop engages participants with short activities to understand key challenges of food security in Singapore. Participants are introduced to critical-design thinking tools through which the facilitators model the asking of good questions. At the end of the workshop, participants gain insights from a discussion of case studies that leverage on digital solutions to enhance the resilience of Singapore’s food supply.
 Criticality is in built within the design education and as such, criticality is intuitive for designers. Also, design thinking has been touted as an inclusive tool for non-designers. However, on its own, it can be problematic without an explicit framework for criticality. The intentional integration of critical-design thinking in our adopted framework allows for an explicit application of a structure. This effectively guides the convergent and divergent thinking in the design innovation approach. Thus, demystifying the process of truly uncovering and understanding issues, and creating innovative solutions. When good questions are asked, we will get to reframe the way problems are viewed and consequently solved. It is with the use of critical questions that we get to evaluate and achieve the best of our thinking. Hence, the workshop aims to bring awareness to participants the importance of understanding the relationship between critical thinking and design thinking in the design innovation approach. It highlights the need for us to achieve creative confidence and critical competence when ideating for solutions to solve real world problems.
Quantum corrections to the magnetoconductivity of surface states in three-dimensional topological insulators
Creators: name: Shi, Gang
name: Gao, Fan
name: Li, Zhilin
name: Zhang, Rencong
name: Gornyi, Igor
name: Gutman, Dmitri
name: Li, Yongqing
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The interplay between quantum interference, electron-electron interaction (EEI), and disorder is one of the central themes of condensed matter physics. Such interplay can cause high-order magnetoconductance (MC) corrections in semiconductors with weak spin-orbit coupling (SOC). However, it remains unexplored how the magnetotransport properties are modified by the high-order quantum corrections in the electron systems of symplectic symmetry class, which include topological insulators (TIs), Weyl semimetals, graphene with negligible intervalley scattering, and semiconductors with strong SOC. Here, we extend the theory of quantum conductance corrections to two-dimensional electron systems with the symplectic symmetry, and study experimentally such physics with dual-gated TI devices in which the transport is dominated by highly tunable surface states. We find that the MC can be enhanced significantly by the second-order interference and the EEI effects, in contrast to suppression of MC for the systems with orthogonal symmetry. Our work reveals that detailed MC analysis can provide deep insights into the complex electronic processes in TIs, such as the screening and dephasing effects of localized charge puddles, as well as the related particle-hole asymmetry.
description: 6 pages, 4 figures