cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Inverse design of functional photonic patches by adjoint optimization coupled to the generalized Mie theory
Creators: name: Zhu, Yilin
name: Chen, Yuyao
name: Gorsky, Sean
name: Shubitidze, Tornike
name: Negro, Luca Dal
Publisher: name: arXiv
Year: 2023
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We propose a rigorous approach for the inverse design of functional photonic structures by coupling the adjoint optimization method and the two-dimensional generalized Mie theory (2D-GMT) for the multiple scattering problem of finite-size arrays of dielectric nanocylinders optimized to display desired functions. We refer to these functional scattering structures as "photonic patches". We briefly introduce the formalism of 2D-GMT and the critical steps necessary to implement the adjoint optimization algorithm to photonic patches with designed radiation properties. In particular, we showcase several examples of periodic and aperiodic photonic patches with optimal nanocylinder radii and arrangements for radiation shaping, wavefront focusing in the Fresnel zone, and for the enhancement of the local density of states (LDOS) at multiple wavelengths over micron-size areas. Moreover, we systematically compare the performances of periodic and aperiodic patches with different sizes and find that optimized aperiodic Vogel spiral geometries feature significant advantages in achromatic focusing compared to their periodic counterparts. Our results show that adjoint optimization coupled to 2D-GMT is a robust methodology for the inverse design of compact photonic devices that operate in the multiple scattering regime with optimal desired functionalities. Without the need of spatial meshing, our approach provides efficient solutions at strongly reduced computational burden compared to standard numerical optimization techniques and suggests compact device geometries for on-chip photonics and metamaterials technologies.
Vulnerability of linear systems against sensor attacks--a system's security index
Creators: name: Chong, Michelle S.
name: Kuijper, Margreta
Publisher: name: arXiv
Year: 2016
Subjects: subject: Systems and Control (eess.SY)
subject: Cryptography and Security (cs.CR)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences
subject: 93B35, 94B05

description: The `security index' of a discrete-time LTI system under sensor attacks is introduced as a quantitative measure on the security of an observable system. We derive ideas from error control coding theory to provide sufficient conditions for attack detection and correction.
description: Submitted
EMPRESS. XI. SDSS and JWST Search for Local and z~4-5 Extremely Metal-Poor Galaxies (EMPGs): Clustering and Chemical Properties of Local EMPGs
Creators: name: Nishigaki, Moka
name: Ouchi, Masami
name: Nakajima, Kimihiko
name: Ono, Yoshiaki
name: Rauch, Michael
name: Isobe, Yuki
name: Harikane, Yuichi
name: Narita, Kanako
name: Zahedy, Fakhri
name: Xu, Yi
name: Yajima, Hidenobu
name: Fukushima, Hajime
name: Hirai, Yutaka
name: Kim, Ji Hoon
name: Inoue, Shigeki
name: Kusakabe, Haruka
name: Lee, Chien-Hsiu
name: Nagao, Tohru
name: Onodera, Masato
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We search for local extremely metal-poor galaxies (EMPGs), selecting photometric candidates by broadband color excess and machine-learning techniques with the SDSS photometric data. After removing stellar contaminants by shallow spectroscopy with Seimei and Nayuta telescopes, we confirm that three candidates are EMPGs with 0.05--0.1 $Z_\odot$ by deep Magellan/MagE spectroscopy for faint {\sc[Oiii]}$λ$4363 lines. Using a statistical sample consisting of 105 spectroscopically-confirmed EMPGs taken from our study and the literature, we calculate cross-correlation function (CCF) of the EMPGs and all SDSS galaxies to quantify environments of EMPGs. Comparing another CCF of all SDSS galaxies and comparison SDSS galaxies in the same stellar mass range ($10^{7.0}-10^{8.4} M_\odot$), we find no significant ($>1σ$) difference between these two CCFs. We also compare mass-metallicity relations (MZRs) of the EMPGs and those of galaxies at $z\sim$ 0--4 with a steady chemical evolution model and find that the EMPG MZR is comparable with the model prediction on average. These clustering and chemical properties of EMPGs are explained by a scenario of stochastic metal-poor gas accretion on metal-rich galaxies showing metal-poor star formation. Extending the broadband color-excess technique to a high-$z$ EMPG search, we select 17 candidates of $z\sim$ 4--5 EMPGs with the deep ($\simeq30$ mag) near-infrared JWST/NIRCam images obtained by ERO and ERS programs. We find galaxy candidates with negligible {\sc[Oiii]}$λλ$4959,5007 emission weaker than the local EMPGs and known high-$z$ galaxies, suggesting that some of these candidates may fall in 0--0.01 $Z_\odot$, which potentially break the lowest metallicity limit known to date.
'Spectro-temporal' variabilities and possible physical mechanism for Jet ejections
Creators: name: D., Radhika
name: Nandi, A.
name: Agrawal, V. K.
name: Seetha, S.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: In this paper, we attempt to find out the `spectro-temporal' characteristics during the jet ejection, of several outbursting Galactic black hole sources based on RXTE-PCA/HEXTE data in the energy band of 2 - 100 keV. We present results of detailed analysis of these sources during the rising phase of their outburst, whenever simultaneous or near-simultaneous X-ray and Radio observations are `available'. We find that before the peak radio flare (transient jet) a few of the sources (in addition to those reported earlier) exhibit `local' softening within the soft intermediate state itself. Except the duration, all the properties of the `local' softening (QPO not observed, reduction in total rms, soft spectra) are observed to be similar to the canonical soft state. We find similar `local' softening for the recent outburst of V404 Cyg also based on SWIFT observations. Fast changes in the `spectro-temporal' properties during the `local' softening implies that it may not be occurring due to change in Keplerian accretion rate. We discuss these results in the framework of the magnetized two component advective flow model.
description: Accepted for publication in MNRAS
Signals of a New Gauge Boson from IceCube and Muon $g-2$
Creators: name: Hooper, Dan
name: Juan, Joaquim Iguaz
name: Serpico, Pasquale D.
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: A $Z'$ boson associated with a broken $U(1)_{L_μ - L_τ}$ gauge symmetry offers an economical solution to the long-standing $g_μ-2$ anomaly, confirmed and strengthened by recent measurements at Fermilab. Here, we revisit the impact of such a $Z'$ on the spectrum of high-energy astrophysical neutrinos, as measured by the IceCube experiment. This spectrum has been observed to exhibit a dip-like feature at $E_ν \sim 0.2-1 \, {\rm PeV}$, which could plausibly arise from the physics of the sources themselves, but could also be the consequence of high-energy neutrinos resonantly scattering with the cosmic neutrino background, mediated by a $Z'$ with a mass on the order of $m_{Z'} \sim 10 \, {\rm MeV}$. In this study, we calculate the impact of such a $Z'$ on the high-energy neutrino spectrum for a variety of model parameters and source distributions. For couplings that can resolve the $g_μ-2$ anomaly, we find that this model could self-consistently produce a spectral feature that is consistent with IceCube's measurement, in particular if the neutrinos observed by IceCube predominantly originate from high-redshift sources.
description: 15 pages, 11 figures
Cluster Toroidal Multipoles Formed by Electric-Quadrupole and Magnetic-Octupole Trimers: A Possible Scenario for Hidden Orders in Ca$_5$Ir$_3$O$_{12}$
Creators: name: Hayami, Satoru
name: Tsutsui, Satoshi
name: Hanate, Hiroki
name: Nagasawa, Nobumoto
name: Yoda, Yoshitaka
name: Matsuhira, Kazuyuki
Publisher: name: arXiv
Year: 2023
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Cluster multipole orderings composed of atomic high-rank multipole moments are theoretically investigated with a 5$d$-electron compound Ca$_5$Ir$_3$O$_{12}$ in mind. Ca$_5$Ir$_3$O$_{12}$ exhibits two hidden orders: One is an intermediate-temperature phase with time-reversal symmetry and the other is a low-temperature phase without time-reversal symmetry. By performing the symmetry and augmented multipole analyses for a $d$-orbital model under the hexagonal point group $D_{\rm 3h}$, we find that the 120$^{\circ}$-type ordering of the electric quadrupole corresponds to cluster electric toroidal dipole ordering with the electric ferroaxial moment, which can become the microscopic origin of the intermediate-temperature phase in Ca$_5$Ir$_3$O$_{12}$. Furthermore, based on ${}^{193}$Ir synchrotron-radiation-based Mössbauer spectroscopy, we propose that the low-temperature phase in Ca$_5$Ir$_3$O$_{12}$ is regarded as a coexisting state with cluster electric toroidal dipole and cluster magnetic toroidal quadrupole, the latter of which is formed by the 120$^{\circ}$-type ordering of the magnetic octupole and accompanies a small uniform magnetization as a secondary effect. Our results provide a clue to two hidden phases in Ca$_5$Ir$_3$O$_{12}$.
description: 6 pages, 4 figures, 1 table, accepted for publication in JPSJ
Volume complexity of dS bubbles
Creators: name: Auzzi, Roberto
name: Nardelli, Giuseppe
name: Ungureanu, Gabriel Pedde
name: Zenoni, Nicolo
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In the framework of the static patch approach to de Sitter holography introduced in [arXiv:2109.14104], the growth of holographic complexity has a hyperfast behaviour, which leads to a divergence in a finite time. This is very different from the AdS spacetime, where instead the complexity rate asymptotically reaches a constant value. We study holographic volume complexity in a class of asymptotically AdS geometries which include de Sitter bubbles in their interior. With the exception of the static bubble case, the complexity obtained from the volume of the smooth extremal surfaces which are anchored just to the AdS boundary has a similar behaviour to the AdS case, because it asymptotically grows linearly with time. The static bubble configuration has a zero complexity rate and corresponds to a discontinuous behaviour, which resembles a first order phase transition. If instead we consider extremal surfaces which are anchored at both the AdS boundary and the de Sitter stretched horizon, we find that complexity growth is hyperfast, as in the de Sitter case.
description: 30 pages, 27 figures; v2: journal version
Optimal nonlinear coherent mode transitions in Bose-Einstein Condensates utilizing spatio-temporal controls
Creators: name: Hocker, David
name: Yan, Julia
name: Rabitz, Herschel
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Bose-Einstein condensates (BECs) offer the potential to examine quantum behavior at large length and time scales, as well as forming promising candidates for quantum technology applications. Thus, the manipulation of BECs using control fields is a topic of prime interest. We consider BECs in the mean field model of the Gross-Pitaevskii equation (GPE), which contains linear and nonlinear features, both of which are subject to control. In this work we report successful optimal control simulations of a one dimensional GPE by modulating the linear and nonlinear terms to stimulate transitions into excited coherent modes. The linear and nonlinear controls are allowed to freely vary over space and time to seek their optimal forms. The determination of the excited coherent modes targeted for optimization is numerically performed through an adaptive imaginary time propagation method. Numerical simulations are performed for optimal control of mode-to-mode transitions between the ground coherent mode and excited modes of a BEC trapped in a harmonic well. The results show greater than 99% success for nearly all trials utilizing reasonable initial guesses for the controls, and analysis of the optimal controls reveals primarily direct transitions between initial and target modes. The success of using solely the nonlinearity term as a control opens up further research toward exploring novel control mechanisms inaccessible to linear Schrödinger-type systems.
description: 13 pages, 8 figures
Transverse single-spin asymmetries of mid-rapidity pi0 and eta mesons in 200 GeV p+Al and p+Au collisions from PHENIX
Creators: name: Fitzgerald, Dillon
Publisher: name: Zenodo
Year: 2023
Subjects: spin23
phenix
p+al
p+au
spin
transverse spin asymmetry
mid-rapidity
π0
η
gluon

description: Talk presented at the International Spin Symposium (SPIN) 2023 conference
Dynamics of Coulombic and Gravitational Periodic Systems
Creators: name: Kumar, Pankaj
name: Miller, Bruce N.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: We study the dynamics and the phase-space structures of Coulombic and self-gravitating versions of the classical one-dimensional 3-body system with periodic boundary conditions. We demonstrate that such a 3-body system may be reduced isomorphically to a spatially periodic system of a single particle experiencing a two-dimensional potential on a rhombic plane. For the case of both Coulombic and gravitational versions, exact expressions of the Hamiltonian have been derived in rhombic coordinates. We simulate the phase-space evolution through an event-driven algorithm that utilizes analytic solutions to the equations of motion. The simulation results show that the motion exhibits chaotic, quasiperiodic, and periodic behaviors in segmented regions of the phase space. While there is no evidence of global chaos in either the Coulombic or the gravitational system, the former exhibits a transition from a completely non-chaotic phase space at low energies to a mixed behavior. Gradual yet striking transitions from mild to intense chaos are indicated with changing energy, a behavior that differentiates the spatially periodic systems studied in this paper from the well-understood free-boundary versions of the 3-body problem. Our treatment of the 3-body systems is the first one of its kind and opens avenues for analysis of the dynamical properties exhibited by spatially periodic versions of various classes of systems studied in plasma and gravitational physics as well as in cosmology.
description: 5 pages, 2 figures
Automated Parton-Shower Variations in Pythia 8
Creators: name: Mrenna, S.
name: Skands, P.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In the era of precision physics measurements at the LHC, efficient and exhaustive estimations of theoretical uncertainties play an increasingly crucial role. In the context of Monte Carlo (MC) event generators, the estimation of such uncertainties traditionally requires independent MC runs for each variation, for a linear increase in total run time. In this work, we report on an automated evaluation of the dominant (renormalization-scale and non-singular) perturbative uncertainties in the PYTHIA 8 event generator, with only a modest computational overhead. Each generated event is accompanied by a vector of alternative weights (one for each uncertainty variation), with each set separately preserving the total cross section. Explicit scale-compensating terms can be included, reflecting known coefficients of higher-order splitting terms and reducing the effect of the variations. The formalism also allows for the enhancement of rare partonic splittings, such as $g \to b \bar{b}$ and $q\to q γ$, to obtain weighted samples enriched in these splittings while preserving the correct physical Sudakov factors.
description: 19 pages, 12 figures
Predictions and Measurements of Thermal Conductivity of Ceramic Materials at High Temperature
Creators: name: Han, Zherui
name: Xiong, Zixin
name: Riffe, William T.
name: Schonfeld, Hunter B.
name: Segovia, Mauricio
name: Song, Jiawei
name: Wang, Haiyan
name: Xu, Xianfan
name: Hopkins, Patrick E.
name: Marconnet, Amy
name: Ruan, Xiulin
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: The lattice thermal conductivity ($κ$) of two ceramic materials, cerium dioxide (CeO$_2$) and magnesium oxide (MgO), is computed up to 1500 K using first principles and the phonon Boltzmann Transport Equation (PBTE) and compared to time-domain thermoreflectance (TDTR) measurements up to 800 K. Phonon renormalization and the four-phonon effect, along with high temperature thermal expansion, are integrated in our \textit{ab initio} molecular dynamics (AIMD) calculations. This is done by first relaxing structures and then fitting to a set of effective force constants employed in a temperature-dependent effective potential (TDEP) method. Both three-phonon and four-phonon scattering rates are computed based on these effective force constants. Our calculated thermal conductivities from the PBTE solver agree well with literature and our TDTR measurements. Other predicted thermal properties including thermal expansion, frequency shift, and phonon linewidth also compare well with available experimental data. Our results show that high temperature softens phonon frequency and reduces four-phonon scattering strength in both ceramics. Compared to MgO, we find that CeO$_2$ has weaker four-phonon effect and renormalization greatly reduces its four-phonon scattering rates.
Transfer matrix approach to 1d random band matrices: density of states
Creators: name: Shcherbina, Mariya
name: Shcherbina, Tatyana
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We study the special case of $n\times n$ 1D Gaussian Hermitian random band matrices, when the covariance of the elements is determined by the matrix $J=(-W^2\triangle+1)^{-1}$. Assuming that $n\ge CW\log W\gg 1$, we prove that the averaged density of states coincides with the Wigner semicircle law up to the correction of order $W^{-1}$.
description: 27 p
Orbitally driven spin reorientation in Mn doped YBaCuFeO$_{5}$
Creators: name: Sharma, Mukesh
name: Maitra, T.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Oxygen-deficient layered perovskite YBaCuFeO$_{5}$ (YBCFO) is one rare type-II multiferroic material where ferroelectricity, driven by incommensurate spiral magnetic order, is believed to be achievable up to temperatures higher than room temperature. A cycloidal spiral rather than helical spiral order is essential ingredient for the existence of ferroelectricity in this material. Motivated by a recent experimental work on Mn-doped YBCFO where the spiral plane is observed to cant more towards the crystallographic $c$ axis upon Mn doping at Fe sites compared to that in the parent compound, we performed a detailed theoretical investigation using the density functional theory calculations to understand the mechanism behind such spin reorientation. Our total energy calculations, within GGA+U+SO approximation, reveal that Fe/Cu spin moments indeed align more towards $c$ axis in the Mn-doped compounds than they were in parent compound YBCFO. Largest exchange interaction (Cu-Cu in the $ab$-plane) is observed to decrease systematically with Mn doping concentration reflecting the lowering of transition temperature seen in experiment. Further, the inter-bilayer Cu-Mn exchange interaction becomes ferromagnetic in the doped compound whereas the corresponding Cu-Fe exchange was antiferromagnetic in the parent compound giving rise to frustration in the commensurate magnetic order. Most importantly, our electronic structure calculations reveal that in the doped compounds because of hybridization with the d$_{z^2}$ orbital of Mn, the highest occupied Cu orbital becomes d$_{z^2}$ as opposed to the parent compound where the highest occupied Cu orbital is d$_{x^2-y^2}$. Therefore, we believe that the occupancy of out of plane oriented Cu d$_{z^2}$ orbital in place of planar d$_{x^2-y^2}$ orbital along with the frustrating exchange interaction drive the spins to align along $c$ in doped compound.
Ernodesmis Borgesen 1912
Creators: name: Mora-Valdés, Laura Areli
name: Riosmena-Rodríguez, Rafael
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Plantae
Chlorophyta
Ulvophyceae
Siphonocladales
Siphonocladaceae
Ernodesmis

description: Ernodesmis Børgesen (1912: 259)
 Ernodesmis verticillata (Kützing) Børgensen (1912: 259).
TAXONOMIC STATUS: According to Norris (2010) and Guiry & Guiry (2014) this name is currently taxonomicaly valid.
 RECORDS IN THE GULF OF CALIFORNIA: Cabeza Ballena (Dawson 1949: 245), Puerto Peñasco (Dawson 1966a: 6, Dawson 1966b: 55), Bahía Concepción (Mateo-Cid et al. 1993: table 1), Bahía de La Paz (Dawson 1961: 379, Huerta-Múzquiz & Mendoza-González 1985: 44, Riosmena-Rodríguez & Paúl-Chávez 1997: 67), Calerita (Rodríguez-Morales & Siqueiros-Beltrones 1999: 22), Punta Arena and Cabo Pulmo (Mateo-Cid et al. 2000: 70), Isla Espíritu Santo and Isla La Partida (Dawson 1959: 8, 11, Paúl-Chávez & Riosmena-Rodríguez 2000: 146), Northern Gulf (Norris 2010: 75). Unpublished data: Castillo-Álvarez (1990: 83, table1), Vázquez-Borja (1999: table 1, 2).
description: Published as part of Mora-Valdés, Laura Areli & Riosmena-Rodríguez, Rafael, 2016, Checklist of the green (Ulvophyceae) macroalgae from the Gulf of California, México, pp. 203-247 in Phytotaxa 246 (4) on page 234, DOI: 10.11646/phytotaxa.246.4.1, http://zenodo.org/record/13678608
Emergent States in Systems of Chiral Self-Propelled Rods
Creators: name: Kürsten, Rüdiger
name: Levis, Demian
Publisher: name: arXiv
Year: 2023
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: We study inherently chiral self-propelled particles, self-rotating at a fixed frequency, in two dimensions, subjected to nematic alignment interactions and rotational noise. By means of both, homogeneous and spatially resolved mean field kinetic theory, we identify various different flocking states. We confirm the presence of the predicted phases using agent-based simulations, in particular, an homogeneous nematic phase at low frequencies, followed by a microflock pattern phase at larger frequencies, characterized by finite-size nematic clusters. We emphasize that special care has to be taken within the simulations in order to avoid artifacts, and present a non-standard simulation technique in order to avoid them.
description: 10 pages, 4 figures
Presence of liquid water during the evolution of exomoons orbiting ejected free-floating planets
Creators: name: Roccetti, Giulia
name: Grassi, Tommaso
name: Ercolano, Barbara
name: Molaverdikhani, Karan
name: Crida, Aurélien
name: Braun, Dieter
name: Chiavassa, Andrea
Publisher: name: arXiv
Year: 2023
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Free-floating planets (FFPs) can result from dynamical scattering processes happening in the first few million years of a planetary system's life. Several models predict the possibility, for these isolated planetary-mass objects, to retain exomoons after their ejection. The tidal heating mechanism and the presence of an atmosphere with a relatively high optical thickness may support the formation and maintenance of oceans of liquid water on the surface of these satellites. In order to study the timescales over which liquid water can be maintained, we perform dynamical simulations of the ejection process and infer the resulting statistics of the population of surviving exomoons around free-floating planets. The subsequent tidal evolution of the moons' orbital parameters is a pivotal step to determine when the orbits will circularize, with a consequential decay of the tidal heating. We find that close-in ($a \lesssim 25 $R$_{\rm J}$) Earth-mass moons with CO$_2$-dominated atmospheres could retain liquid water on their surfaces for long timescales, depending on the mass of the atmospheric envelope and the surface pressure assumed. Massive atmospheres are needed to trap the heat produced by tidal friction that makes these moons habitable. For Earth-like pressure conditions ($p_0$ = 1 bar), satellites could sustain liquid water on their surfaces up to 52 Myr. For higher surface pressures (10 and 100 bar), moons could be habitable up to 276 Myr and 1.6 Gyr, respectively. Close-in satellites experience habitable conditions for long timescales, and during the ejection of the FFP remain bound with the escaping planet, being less affected by the close encounter.
description: 21 pages, 12 figures, accepted for publication on International Journal of Astrobiology
Polarization measurements of hot dust stars and the local interstellar medium
Creators: name: Marshall, J. P.
name: Cotton, D. V.
name: Bott, K.
name: Ertel, S.
name: Kennedy, G. M.
name: Wyatt, M. C.
name: del Burgo, C.
name: Absil, O.
name: Bailey, J.
name: Kedziora-Chudczer, L.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Debris discs are typically revealed through excess emission at infrared wavelengths. Most discs exhibit excess at mid- and far-infrared wavelengths, analogous to the solar system's Asteroid and Edgeworth-Kuiper belts. Recently, stars with strong (1 per cent) excess at near-infrared wavelengths were identified through interferometric measurements. Using the HIgh Precision Polarimetric Instrument (HIPPI), we examined a sub-sample of these hot dust stars (and appropriate controls) at parts-per-million sensitivity in SDSS g' (green) and r' (red) filters for evidence of scattered light. No detection of strongly polarized emission from the hot dust stars is seen. We therefore rule out scattered light from a normal debris disk as the origin of this emission. A wavelength dependent contribution from multiple dust components for hot dust stars is inferred from the dispersion (difference in polarization angle in red and green) of southern stars. Contributions of 17 ppm (green) and 30 ppm (red) are calculated, with strict 3 sigma upper limits of 76 and 68 ppm, respectively. This suggests weak hot dust excesses consistent with thermal emission, although we cannot rule out contrived scenarios, e.g. dust in a spherical shell or face on discs. We also report on the nature of the local interstellar medium, obtained as a byproduct of the control measurements. Highlights include the first measurements of the polarimetric colour of the local interstellar medium and discovery of a southern sky region with a polarization per distance thrice the previous maximum. The data suggest the wavelength of maximum polarization is bluer than typical.
description: 11 pages, 5 tables, 3 figures, accepted for publication in ApJ
Demystifying the twistor construction of composite operators in N=4 super-Yang-Mills theory
Creators: name: Chicherin, Dmitry
name: Sokatchev, Emery
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We explain some details of the construction of composite operators in N=4 SYM that we have elaborated earlier in the context of Lorentz harmonic chiral (LHC) superspace. We give a step-by-step elementary derivation and show that the result coincides with the recent hypothesis put forward in arXiv:1603.04471 within the twistor approach. We provide the appropriate LHC-to-twistors dictionary.
description: 10 pages
Collective motion patterns of swarms with delay coupling: theory and experiment
Creators: name: Szwaykowska, Klementyna
name: Schwartz, Ira B.
name: Romero, Luis Mier-y-Teran
name: Heckman, Christoffer R.
name: Mox, Dan
name: Hsieh, M. Ani
Publisher: name: arXiv
Year: 2016
Subjects: subject: Adaptation and Self-Organizing Systems (nlin.AO)
subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: The formation of coherent patterns in swarms of interacting self-propelled autonomous agents is a subject of great interest in a wide range of application areas, ranging from engineering and physics to biology. In this paper, we model and experimentally realize a mixed-reality large-scale swarm of delay-coupled agents. The coupling term is modeled as a delayed communication relay of position. Our analyses, assuming agents communicating over an Erdos-Renyi network, demonstrate the existence of stable coherent patterns that can only be achieved with delay coupling and that are robust to decreasing network connectivity and heterogeneity in agent dynamics. We also show how the bifurcation structure for emergence of different patterns changes with heterogeneity in agent acceleration capabilities and limited connectivity in the network as a function of coupling strength and delay. Our results are verified through simulation as well as preliminary experimental results of delay-induced pattern formation in a mixed-reality swarm.
description: 11 pages, 11 Figures. arXiv admin note: text overlap with arXiv:1507.03586
Large-scale Ising spin network based on degenerate optical parametric oscillators
Creators: name: Inagaki, Takahiro
name: Inaba, Kensuke
name: Hamerly, Ryan
name: Inoue, Kyo
name: Yamamoto, Yoshihisa
name: Takesue, Hiroki
Publisher: name: arXiv
Year: 2016
Subjects: subject: Optics (physics.optics)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Simulating a network of Ising spins with physical systems is now emerging as a promising approach for solving mathematically intractable problems. Here we report a large-scale network of artificial spins based on degenerate optical parametric oscillators (DOPO), paving the way towards a photonic Ising machine capable of solving difficult combinatorial optimization problems. We generated >10,000 time-division-multiplexed DOPOs using dual-pump four-wave mixing (FWM) in a highly nonlinear fibre (HNLF) placed in a fibre cavity. Using those DOPOs, a one-dimensional (1D) Ising model was simulated by introducing nearest-neighbour optical coupling. We observed the formation of spin domains and found that the domain size diverged near the DOPO threshold, which suggests that the DOPO network can simulate the behavior of low-temperature Ising spins.
description: 6 pages, 3 figures. First draft in Nature Photonics (2016)
Bridging the Gap between Requirements Engineering and Model Evaluation in Machine Learning
Creators: name: Turri, Violet
name: Heim, Eric
Publisher: name: Carnegie Mellon University
Year: 2022
Subjects: subject: 80309 Software Engineering
subject: FOS: Computer and information sciences

description: As the use of artificial intelligence (AI) systems in real-world settings has increased, so has demand for assurances that AI-enabled systems perform as intended. Due to the complexity of modern AI systems, the environments they are deployed in, and the tasks they are designed to complete, providing such guarantees remains a challenge. Defining and validating system behaviors through requirements engineering (RE) has been an integral component of software engineering since the 1970s. Despite the longevity of this practice, requirements engineering for machine learning (ML) is not standardized and, as evidenced by interviews with ML practitioners and data scientists, is considered one of the hardest tasks in ML development. In this post, we define a simple evaluation framework centered around validating requirements and demonstrate this framework on an autonomous vehicle example. We hope that this framework will serve as (1) a starting point for practitioners to guide ML model development and (2) a touchpoint between the software engineering and machine learning research communities.
Critical temperature of trapped interacting bosons from large-N based theories
Creators: name: Kim, Tom
name: Chien, Chih-Chun
Publisher: name: arXiv
Year: 2015
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Ultracold atoms provide clues to an important many-body problem regarding the dependence of Bose-Einstein condensation (BEC) transition temperature $T_c$ on interactions. However, cold atoms are trapped in harmonic potentials and theoretical evaluations of the $T_c$ shift of trapped interacting Bose gases are challenging. While previous predictions of the leading-order shift have been confirmed, more recent experiments exhibit higher-order corrections beyond available mean-field theories. By implementing two large-N based theories with the local density approximation (LDA), we extract next-order corrections of the $T_c$ shift. The leading-order large-N theory produces results quantitatively different from the latest experimental data. The leading-order auxiliary field (LOAF) theory containing both normal and anomalous density fields captures the $T_c$ shift accurately in the weak interaction regime. However, the LOAF theory shows incompatible behavior with the LDA and forcing the LDA leads to density discontinuities in the trap profiles. We present a phenomenological model based on the LOAF theory, which repairs the incompatibility and provides a prediction of the $T_c$ shift in stronger interaction regime.
description: 11 pages, 3 figures
Generalized method of image dyons for quasi-two dimensional slabs with ordinary-topological insulator interfaces
Creators: name: Movilla, Jose L.
name: Climente, Juan I.
name: Planelles, J.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Electrostatic charges near the interface bewteen topological (TI) and ordinary (OI) insulators induce magnetic fields in the medium that can be described through the so-called method of image dyons (electric charge - magnetic monopole pairs), the magnetoelectric extension of the method of image charges in classical electrostatics. Here, we provide the expressions for the image dyons and ensuing magnetoelectric potentials in a system comprised by two planar-parallel OI-TI interfaces conforming a finite-width slab. The obtained formulae extend earlier work in that they account for all different combinations of materials forming the slab and its surroundings, including asymmetric systems, as well as all possible combinations of external magnetization orientations on the interfaces. The equations are susceptible of implementation in simple computational codes, to be solved recurrently, in order to model magnetoelectric fields in topological quantum wells, thin films, or layers of two-dimensional materials. We exemplify this by calculating the magnetic fields induced by a point charge in nanometer-thick quantum wells, by means of a Mathematica code made available in repositories.
description: 9 pages, 7 figures
Can an interdisciplinary field contribute to one of the parent disciplines from which it emerged?
Creators: name: Chakraborti, Anirban
name: Raina, Dhruv
name: Sharma, Kiran
Publisher: name: arXiv
Year: 2016
Subjects: subject: Physics and Society (physics.soc-ph)
subject: General Finance (q-fin.GN)
subject: FOS: Physical sciences
subject: FOS: Economics and business

description: In the light of contemporary discussions of inter and transdisciplinarity, this paper approaches econophysics and sociophysics to seek a response to the question -- whether these interdisciplinary fields could contribute to physics and economics. Drawing upon the literature on history and philosophy of science, the paper argues that the two way traffic between physics and economics has a long history and this is likely to continue in the future.
description: 9 pages, EPJ format. To appear in the European Physical Journal Special Topics, entitled "Can economics be a physical science?" Eds. A.S. Chakrabarti et al
Simultaneous polarization squeezing in polarized N photon state and diminution on a squeezing operation
Creators: name: Shukla, Namrata
name: Prakash, Ranjana
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We study polarization squeezing of a pure photon number state which is obviously polarized but the mere change in the basis of polarization leads to simultaneous polarization squeezing in all the components of Stokes operator vector except those falling along or perpendicular to the direction of polarization state, is observed. We use the most general definition of polarization squeezing and discuss the experimental feasibility of the result. We also observe that a squeezing operation like non-degenerate parametric amplification of the state does not reveal simultaneous squeezing in all Stokes operator vectors and decreases in this sense.
description: 5 pages, 2 figures
Bridging the Gap between Requirements Engineering and Model Evaluation in Machine Learning
Creators: name: Turri, Violet
Publisher: name: Carnegie Mellon University
Year: 2022
Subjects: subject: 80309 Software Engineering
subject: FOS: Computer and information sciences

description: As the use of artificial intelligence (AI) systems in real-world settings has increased, so has demand for assurances that AI-enabled systems perform as intended. Due to the complexity of modern AI systems, the environments they are deployed in, and the tasks they are designed to complete, providing such guarantees remains a challenge. Defining and validating system behaviors through requirements engineering (RE) has been an integral component of software engineering since the 1970s. Despite the longevity of this practice, requirements engineering for machine learning (ML) is not standardized and, as evidenced by interviews with ML practitioners and data scientists, is considered one of the hardest tasks in ML development. In this post, we define a simple evaluation framework centered around validating requirements and demonstrate this framework on an autonomous vehicle example. We hope that this framework will serve as (1) a starting point for practitioners to guide ML model development and (2) a touchpoint between the software engineering and machine learning research communities.
Coptera pomonellae Muesebeck 1980
Creators: name: Notton, David G.
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Diapriidae
Coptera
Coptera pomonellae

description: Coptera pomonellae Muesebeck, 1980: 23, 26, 44, figs 80, 100, 119.
Valid name
Coptera pomonellae Muesebeck, 1980.
Summary of types
Paratype ♂.
description: Published as part of Notton, David G., 2014, A catalogue of the types of Diapriinae (Hymenoptera, Diapriidae) at the Natural History Museum, London, pp. 1-123 in European Journal of Taxonomy 75 on page 85, DOI: 10.5852/ejt.2014.75, http://zenodo.org/record/3862773
Quantization of entropy in a quasi-two-dimensional electron gas
Creators: name: Varlamov, A. A.
name: Kavokin, A. V.
name: Galperin, Yu. M.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: We demonstrate that the partial entropy of a two-dimensional electron gas (2DEG) exhibits quantized peaks at resonances between the chemical potential and electron levels of size quantization. In the limit of no scattering, the peaks depend only on the subband quantization number and are independent on material parameters, shape of the confining potential, electron effective mass and temperature. The quantization of partial entropy is a signature of a topological phase transition in a 2DEG. In the presence of stationary disorder, the magnitude of peaks decreases. Its deviation from the quantized values is a direct measure of the disorder induced smearing of the electronic density of states.
description: 4 pages, 2 figures
Two-gap superconductivity in LaNiGa$_2$ with non-unitary triplet pairing and even parity gap symmetry
Creators: name: Weng, Z. F.
name: Zhang, J. L.
name: Smidman, M.
name: Shang, T.
name: Quintanilla, J.
name: Annett, J. F.
name: Nicklas, M.
name: Pang, G. M.
name: Jiao, L.
name: Jiang, W. B.
name: Chen, Y.
name: Steglich, F.
name: Yuan, H. Q.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: The nature of the pairing states of superconducting LaNiC$_2$ and LaNiGa$_2$ has to date remained a puzzling question. Broken time reversal symmetry has been observed in both compounds and a group theoretical analysis implies a non-unitary triplet pairing state. However all the allowed non-unitary triplet states have nodal gap functions but most thermodynamic and NMR measurements indicate fully gapped superconductivity in LaNiC$_2$. Here we probe the gap symmetry of LaNiGa$_2$ by measuring the London penetration depth, specific heat and upper critical field. These measurements demonstrate two-gap nodeless superconductivity in LaNiGa$_2$, suggesting that this is a common feature of both compounds. These results allow us to propose a novel triplet superconducting state, where the pairing occurs between electrons of the same spin, but on different orbitals. In this case the superconducting wavefunction has a triplet spin component but isotropic even parity gap symmetry, yet the overall wavefunction remains antisymmetric under particle exchange. This model leads to a nodeless two-gap superconducting state which breaks time reversal symmetry, and therefore accounts well for the seemingly contradictory experimental results.
description: 5 pages, 4 figures
Accuracy of ghost-rotationally-invariant slave-boson theory for multiorbital Hubbard models and realistic materials
Creators: name: Lee, Tsung-Han
name: Melnick, Corey
name: Adler, Ran
name: Lanatà, Nicola
name: Kotliar, Gabriel
Publisher: name: arXiv
Year: 2023
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We assess the accuracy of the ghost-rotationally-invariant slave-boson (g-RISB) theory in multiorbital systems by applying it to both the three-orbital degenerate Hubbard model and a realistic Sr2RuO4 model extracted from first principle simulations, and comparing the results to those obtained using the dynamical mean-field theory (DMFT). Our findings indicate that g-RISB's accuracy can be systematically improved toward the exact DMFT limit in infinite dimensional multiorbital models by increasing the number of ghost orbitals. This allows for a more precise description of aspects of Hund metal physics and Mott physics compared to the original RISB approach. We also demonstrate that g-RISB reliably captures the quasiparticle weights, Fermi surface, and low-energy spectral function for the realistic Sr2RuO4 model compared to DMFT. Moreover, we showcase the potential of using the density matrix renormalization group method as an impurity solver within the g-RISB framework to study systems with a larger number of ghost orbitals. These results show the potential of g-RISB as a reliable tool for simulating correlated materials. The connection between the g-RISB and DMFT self-energy is also discussed.
Pressure induced re-emergence of superconductivity in superconducting topological insulator Sr0.065Bi2Se3
Creators: name: Zhou, Yonghui
name: Chen, Xuliang
name: Zhang, Ranran
name: Shao, Jifeng
name: Wang, Xuefei
name: An, Chao
name: Zhou, Ying
name: Park, Changyong
name: Tong, Wei
name: Pi, Li
name: Yang, Zhaorong
name: Zhang, Changjin
name: Zhang, Yuheng
Publisher: name: arXiv
Year: 2016
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: The recent-discovered Sr$_x$Bi$_2$Se$_3$ superconductor provides an alternative and ideal material base for investigating possible topological superconductivity. Here, we report that in Sr$_{0.065}$Bi$_{2}$Se$_3$, the ambient superconducting phase is gradually depressed upon the application of external pressure. At high pressure, a second superconducting phase emerges at above 6 GPa, with a maximum $T_c$ value of $\sim$8.3 K. The joint investigations of the high-pressure synchrotron x-ray diffraction and electrical transport properties reveal that the re-emergence of superconductivity in Sr$_{0.065}$Bi$_{2}$Se$_3$ is closely related to the structural phase transition from ambient rhombohedral phase to high-pressure monoclinic phase around 6 GPa, and further to another high-pressure tetragonal phase above 25 GPa.
description: 13 pages, 4 figures
Nonperturbative renormalization of asymmetric staple-shaped operators in twisted mass lattice QCD
Creators: name: Alexandrou, Constantia
name: Bacchio, Simone
name: Cichy, Krzysztof
name: Constantinou, Martha
name: Feng, Xu
name: Jansen, Karl
name: Liu, Chuan
name: Sen, Aniket
name: Spanoudes, Gregoris
name: Steffens, Fernanda
name: Tarello, Jacopo
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Staple-shaped Wilson line operators are necessary for the study of transverse momentum-dependent parton distribution functions (TMDPDFs) in lattice QCD and beyond. In this work, we study the renormalization of such operators in the general case of an asymmetric staple. We analyze the mixing pattern of these operators using their symmetry properties, where we find that the possible mixing is restricted within groups of four operators. We then present numerical results using the regularization independent momentum subtraction (RI/MOM) scheme to study the importance of mixing using one operator in particular, the $γ_0$ operator. Based on these results, we consider the short distance ratio (SDR) scheme, which is desirable in the absence of mixing. Finally, we investigate a variant of the RI/MOM scheme, where the renormalization factors are computed at short distances.
description: 20 pages, 14 figures
Valonia C. Agardh 1823
Creators: name: Mora-Valdés, Laura Areli
name: Riosmena-Rodríguez, Rafael
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Plantae
Chlorophyta
Ulvophyceae
Siphonocladales
Valoniaceae
Valonia

description: Valonia C. Agardh (1823: 428)
 Valonia macrophysa Kützing (1843: 307).
TAXONOMIC STATUS: According to Norris (2010) and Guiry & Guiry (2014) this name is currently taxonomicaly valid.
 RECORDS IN THE GULF OF CALIFORNIA: Bahía de La Paz (Huerta-Múzquiz & Mendoza-González 1985: 44, Riosmena-Rodríguez & Paúl-Chavez 1997: 67), Calerita (Rodríguez-Morales & Siqueiros-Beltrones 1999: 22), Southern Gulf (Norris 2010: 75). Unpublished data: Castillo-Álvarez (1990: 100, table1), Vázquez-Borja (1999: table 1).
description: Published as part of Mora-Valdés, Laura Areli & Riosmena-Rodríguez, Rafael, 2016, Checklist of the green (Ulvophyceae) macroalgae from the Gulf of California, México, pp. 203-247 in Phytotaxa 246 (4) on page 235, DOI: 10.11646/phytotaxa.246.4.1, http://zenodo.org/record/13678608