cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
The relation between the $\bar{\rm MS}$ and the on-shell quark mass at order $α_s^3$
Creators: name: Chetyrkin, K. G.
name: Steinhauser, M.
Publisher: name: arXiv
Year: 1999
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The relation between the on-shell and $\bar{\rm MS}$ mass can be expressed through scalar and vector part of the quark propagator. In principle these two-point functions have to be evaluated on-shell which is a non-trivial task at three-loop order. Instead, we evaluate the quark self energy in the limit of large and small external momentum and use conformal mapping in combination with Padé improvement in order to construct a numerical approximation for the relation [1]. The errors of our final result are conservatively estimated to be below 3%. The numerical implications of the results are discussed in particular in view of top and bottom quark production near threshold. We show that the knowledge of new ${\cal O}(α_s^3)$ correction leads to a significant reduction of the theoretical uncertainty in the determination of the quark masses.
description: 38 pages, misprint in eq.(22) fixed, few references updated and a note added about a recent confirmation of our main results by Melnikov and van Ritbergen (hep-ph/9912391)
On the charge-to-mass ratio for self-gravitating systems of scalar and electromagnetic fields
Creators: name: Kratovich, P. V.
name: Tchemarina, Ju. V.
Publisher: name: arXiv
Year: 2018
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences
subject: 83C22, 83C57

description: We prove that in the family of static, asymptotically flat, spherically symmetric scalar hairy black holes with the central electric charge, the set of the charge-to-mass ratios has the exact upper bound $3\sqrt{2}/4\approx1.06$.
description: 10 pages
Probabilistic Precision and Recall Towards Reliable Evaluation of Generative Models
Creators: name: Park, Dogyun
name: Kim, Suhyun
Publisher: name: arXiv
Year: 2023
Subjects: subject: Machine Learning (cs.LG)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Assessing the fidelity and diversity of the generative model is a difficult but important issue for technological advancement. So, recent papers have introduced k-Nearest Neighbor ($k$NN) based precision-recall metrics to break down the statistical distance into fidelity and diversity. While they provide an intuitive method, we thoroughly analyze these metrics and identify oversimplified assumptions and undesirable properties of kNN that result in unreliable evaluation, such as susceptibility to outliers and insensitivity to distributional changes. Thus, we propose novel metrics, P-precision and P-recall (PP\&PR), based on a probabilistic approach that address the problems. Through extensive investigations on toy experiments and state-of-the-art generative models, we show that our PP\&PR provide more reliable estimates for comparing fidelity and diversity than the existing metrics. The codes are available at \url{https://github.com/kdst-team/Probablistic_precision_recall}.
Zero-point energy of massless scalar fields in the presence of soft and semihard boundaries in D dimensions
Creators: name: Caruso, F.
name: De Paola, R.
name: Svaiter, N. F.
Publisher: name: arXiv
Year: 1998
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The renormalized energy density of a massless scalar field defined in a D-dimensional flat spacetime is computed in the presence of "soft" and "semihard" boundaries, modeled by some smoothly increasing potential functions. The sign of the renormalized energy densities for these different confining situations is investigated. The dependence of this energy on $D$ for the cases of "hard" and "soft/semihard" boundaries are compared.
description: 36 pages, LaTeX, 4 figures
A photo-z cautionary tale: Redshift confirmation of COSBO-7 at z=2.625
Creators: name: Jin, Shuowen
name: Sillassen, Nikolaj B.
name: Hodge, Jacqueline
name: Magdis, Georgios E.
name: Rizzo, Francesca
name: Casey, Caitlin
name: Koekemoer, Anton M.
name: Valentino, Francesco
name: Kokorev, Vasily
name: Magnelli, Benjamin
name: Gobat, Raphael
name: Gillman, Steven
name: Franco, Maximilien
name: Faisst, Andreas
name: Kartaltepe, Jeyhan
name: Schinnerer, Eva
name: Toft, Sune
name: Algera, Hiddo S. B.
name: Harish, Santosh
name: Lee, Minju
name: Liu, Daizhong
name: Shuntov, Marko
name: Talia, Margherita
name: Vijayan, Aswin
Publisher: name: arXiv
Year: 2024
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Photometric redshifts are widely used in studies of dusty star-forming galaxies (DSFGs), but catastrophic photo-$z$ failure can undermine all redshift-dependent results. Here we report the spectroscopic redshift confirmation of COSBO-7, a strongly lensed DSFG in the COSMOS-PRIMER field. Recently, a photometric redshift solution of $z\gtrsim7.0$ was reported for COSBO-7 based on ten bands of {\it James Webb} Space Telescope (JWST) NIRCam and MIRI imaging data. This $z$ value was favored by four independent spectral energy distribution (SED) fitting codes, and the result provided an appealing candidate for the most distant massive DSFG known to date. This photo-$z$ solution was also supported by a single line detection in Atacama Large Millimeter Array (ALMA) Band 3 consistent with CO(7-6) at $z=7.46$. However, our new ALMA observations robustly detect two lines in Band 6 identified as CO(7-6) and [CI](2-1) at $z_{\rm spec}=2.625$, and thus the Band 3 line as CO(3-2). These three robust line detections decidedly place COSBO-7 at $z=2.625$, refuting the photo-$z$ solution. We derive physical parameters by fitting near-infrared(NIR)-to-millimeter(mm) photometry and lens modeling, revealing that COSBO-7 is a main sequence galaxy. We examine possible reasons for this photo-$z$ failure and attribute it to (1) the likely underestimation of photometric uncertainties at 0.9\,$μ$m and 1.15 \,$μ$m; and (2) the lack of photometry at wavelengths beyond 20\,$μ$m. Notably, we recover a bona fide $z_{\rm phot}\sim 2.3$ by including the existing MIPS $24\,μ$m photometry, demonstrating the critical importance of mid-infrared (MIR) data in bolstering photo-$z$ measurements. This work highlights a common challenge in modeling the SEDs of DSFGs, and provides a cautionary tale regarding the reliability of photometric redshifts as well as pseudo-spectroscopic redshifts based on single line detection.
description: Published in A&A
Soft Theorem to Three Loops in QCD and ${\cal N} = 4$ Super Yang-Mills Theory
Creators: name: Chen, Wen
name: Luo, Ming-xing
name: Yang, Tong-Zhi
name: Zhu, Hua Xing
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The soft theorem states that scattering amplitude in gauge theory with a soft gauge-boson emission can be factorized into a hard scattering amplitude and a soft factor. In this paper, we present calculations of the soft factor for processes involving two hard colored partons, up to three loops in QCD. To accomplish this, we developed a systematic method for recursively calculating relevant Feynman integrals using the Feynman-Parameter representation. Our results constitute an important ingredient for the subtraction of infrared singularities at N$^4$LO in perturbative QCD. Using the principle of leading transcendentality between QCD and ${\cal N}=4$ super Yang-Mills theory, we determine the soft factor in the latter case to three loops with full-color dependence. As a by-product, we also obtain the finite constant $f_2^{(3)}$ in the Bern-Dixon-Smirnov ansatz analytically, which was previously known numerically only.
description: 31 pages, ancillary files provided, matches published version
Achieving huge thermal conductance of metallic nitride on graphene through enhanced elastic and inelastic phonon transmission
Creators: name: Zheng, Weidong
name: Huang, Bin
name: Li, Hongkun
name: Koh, Yee Kan
Publisher: name: arXiv
Year: 2018
Subjects: subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: Low thermal conductance of metal contacts is one of the main challenges in thermal management of nanoscale devices of graphene and other 2D materials. Previous attempts to search for metal contacts with high thermal conductance yielded limited success due to incomplete understanding of the origins of the low thermal conductance. In this paper, we carefully study the intrinsic thermal conductance across metal/graphene/metal interfaces to identify the heat transport mechanisms across graphene interfaces. We find that unlike metal contacts on diamond, the intrinsic thermal conductance of most graphene interfaces (except Ti and TiNx) is only about 50 % of the phonon radiation limit, suggesting that heat is carried across graphene interfaces mainly through elastic transmission of phonons. We thus propose a convenient approach to substantially enhance the phononic heat transport across metal contacts on graphene, by better matching the energy of phonons in metals and graphene, e.g., using metallic nitrides. We test the idea with TiNx, with phonon frequencies of up to 1.18*10^14 rad/s, 47 % of the highest phonon frequencies in graphene of 2.51*10^14 rad/s . Interestingly, we obtain a huge thermal conductance of 270 MW m-2 K-1 for TiNx/graphene interfaces, which is about 140 % of the phonon radiation limit. The huge thermal conductance could be partially attributed to inelastic phonon transport across the TiNx/graphene interface. Our work provides guidance for the search for good metal contacts on 2D materials and devices.
Dynamical relaxation of the CP phases in next-to-minimal supersymmetry
Creators: name: Demir, D. A.
Publisher: name: arXiv
Year: 1999
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: After promoting the phases of the soft masses to dynamical fields corresponding to Goldstone bosons of spontaneously broken global symmetries in the supersymmetry breaking sector, the next-to-minimal supersymmetric model is found to solve the $μ$ problem and the strong CP problem simultaneously with an invisible axion. The domain wall problem persists in the form of axionic domain formation. Relaxation dynamics of the physical CP-violating phases is determined only by the short-distance physics and their relaxation values are not necessarily close to the CP-conserving points. Having observable supersymmetric CP violation and avoiding the axionic domain walls both require nonminimal flavor structures.
description: 13 pp, 3 figs, published version
High-Speed Optical Photometry of the Ultracompact X-ray Binary 4U 1626-67
Creators: name: Chakrabarty, Deepto
Publisher: name: arXiv
Year: 1997
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Rapid UBVRI photometry of this ultracompact LMXB pulsar has detected 7.67 s optical pulsations in all five bands. The optical pulsations, which are at the same frequency as the X-ray pulsations, are understood as reprocessing of pulsed X-rays in the accretion disk or on the companion surface. The optical pulsed fraction is 6%, independent of wavelength, indicating that the optical emission is dominated by X-ray reprocessing. A weaker (1.5%) sideband, shifted down 0.395(15) mHz from the main optical pulsation, is also present. This is consistent with a previously reported sideband and corroborating the 42-min binary period proposed earlier by Middleditch et al. (1981). A 0.048 Hz optical QPO, corresponding to a known X-ray feature, was also detected in some of the observations. This is the first measurement of an optical QPO in an X-ray binary pulsar. I discuss constraints on the nature of the mass donor and show that mass transfer via a radiatively-driven wind is inconsistent with the data. I also review the basic theory of X-ray-heated accretion disks and show that such models provide a good fit to the optical photometry. If the X-ray albedo of LMXB accretion disks is as high as recently reported, then the optical data imply a distance of 8 kpc and an X-ray luminosity of 10^37 erg/s.
description: 26 pages including 6 PS figures. Submitted to ApJ
Esthetic Numbers and Lifting Restrictions on the Analysis of Summatory Functions of Regular Sequences
Creators: name: Heuberger, Clemens
name: Krenn, Daniel
Publisher: name: arXiv
Year: 2018
Subjects: subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: 05A16, 11A63, 68Q45, 68R05

description: When asymptotically analysing the summatory function of a $q$-regular sequence in the sense of Allouche and Shallit, the eigenvalues of the sum of matrices of the linear representation of the sequence determine the "shape" (in particular the growth) of the asymptotic formula. Existing general results for determining the precise behavior (including the Fourier coefficients of the appearing fluctuations) have previously been restricted by a technical condition on these eigenvalues. The aim of this work is to lift these restrictions by providing a insightful proof based on generating functions for the main pseudo Tauberian theorem for all cases simultaneously. (This theorem is the key ingredient for overcoming convergence problems in Mellin--Perron summation in the asymptotic analysis.) One example is discussed in more detail: A precise asymptotic formula for the amount of esthetic numbers in the first~$N$ natural numbers is presented. Prior to this only the asymptotic amount of these numbers with a given digit-length was known.
description: to appear in "2019 Proceedings of the Sixteenth Meeting on Analytic Algorithmics and Combinatorics (ANALCO)"
Magnetograms underestimate even unipolar magnetic flux nearly everywhere on the solar disk
Creators: name: Sinjan, Jonas
name: Solanki, Sami K.
name: Hirzberger, Johann
name: Riethmüller, Tino L.
name: Przybylski, Damien
Publisher: name: arXiv
Year: 2024
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We aim to test the reliability of determining the line-of-sight magnetic field from a 3D MHD simulation of a unipolar region. In contrast to earlier similar studies, we consider the full solar disk, i.e. considering the full centre-to-limb variation, as well as regions with different averaged field strengths. We synthesised Stokes profiles from MURaM MHD simulations of unipolar regions with varying mean vertical magnetic flux densities, ranging from quiet Sun to active region plage. We did this for a comprehensive range of heliocentric angles: from $μ=1$ to $μ=0.15$, and for two commonly used photospheric spectral lines: Fe I $6173.3$ and Fe I $5250.2$Å. The line-of-sight magnetic field was derived with a Milne-Eddington Inversion as well as with other commonly used methods. The inferred spatially averaged $\langle B_{LOS}\rangle$ is always lower than that present in the MHD simulations, with the exception of $μ\approx 1$ and sufficiently high spatial resolution. It is also generally inconsistent with a linear dependence on $μ$. Above $μ=0.5$ the spatial resolution greatly impacts the retrieved line-of-sight magnetic field. For $μ\leq0.5$ the retrieved $B_{LOS}$ is nearly independent of resolution, but is always lower than expected from the simulation. These trends persist regardless of the mean vertical magnetic field in the MHD simulations and are independent of the $B_{LOS}$ retrieval method. For $μ\leq0.5$, a larger $\langle B_{LOS}\rangle$ is inferred for the $5250.2$Å spectral line than $6173.3$Å, but the converse is true at higher $μ$. The results found here raise some doubts of the reliability of determining the radial field by dividing the line-of-sight field by $μ$ and are of considerable importance for deducing the total magnetic flux of the Sun. They may also contribute to the resolution of the open flux problem.
description: Submitted to A&A
Cosmic Rays: the salt of the star formation recipe
Creators: name:  ,
Publisher: name: Il Colle di Galileo
Year: 2019

description: A three-day workshop entitled “Cosmic Rays: the salt of the star formation recipe” was held at the Department of Physics and Astronomy of the University of Florence. The proposed workshop had the goal of bringing together experts in theory and simulations of cosmic-ray propagation, astrochemists, and observers to share ideas, discuss recent and present results, and identify the key challenges regarding the chemistry and physics of cosmic rays in the near future.
description: Il Colle di Galileo, Vol 8 No 1 (2019)
Multi-agent Deep Reinforcement Learning for Distributed Load Restoration
Creators: name: Vu, Linh
name: Vu, Tuyen
name: Vu, Thanh-Long
name: Srivastava, Anurag
Publisher: name: arXiv
Year: 2023
Subjects: subject: Systems and Control (eess.SY)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: This paper addresses the load restoration problem after power outage events. Our primary proposed methodology is using multi-agent deep reinforcement learning to optimize the load restoration process in distribution systems, modeled as networked microgrids, via determining the optimal operational sequence of circuit breakers (switches). An innovative invalid action masking technique is incorporated into the multi-agent method to handle both the physical constraints in the restoration process and the curse of dimensionality as the action space of operational decisions grows exponentially with the number of circuit breakers. The features of our proposed method include centralized training for multi-agents to overcome non-stationary environment problems, decentralized execution to ease the deployment, and zero constraint violations to prevent harmful actions. Our simulations are performed in OpenDSS and Python environments to demonstrate the effectiveness of the proposed approach using the IEEE 13, 123, and 8500-node distribution test feeders. The results show that the proposed algorithm can achieve a significantly better learning curve and stability than the conventional methods.
description: 12 pages, 19 figures, journal under review
Ab-initio simulations and measurements of the free-free opacity in Aluminum
Creators: name: Hollebon, P.
name: Ciricosta, O.
name: Desjarlais, M. P.
name: Cacho, C.
name: Spindloe, C.
name: Springate, E.
name: Turcu, I. C. E.
name: Wark, J. S.
name: Vinko, S. M.
Publisher: name: arXiv
Year: 2018
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: The free-free opacity in dense systems is a property that both tests our fundamental understanding of correlated many-body systems, and is needed to understand the radiative properties of high energy-density plasmas. Despite its importance, predictive calculations of the free-free opacity remain challenging even in the condensed matter phase for simple metals. Here we show how the free-free opacity can be modelled at finite-temperatures via time-dependent density functional theory, and illustrate the importance of including local field corrections, core polarization and self-energy corrections. Our calculations for ground-state Al are shown to agree well with experimental opacity measurements performed on the Artemis laser facility across a wide range of x-ray to ultraviolet wavelengths. We extend our calculations across the melt to the warm-dense matter regime, and find good agreement with advanced plasma models based on inverse bremsstrahlung at temperatures above 10 eV.
Permutation Rational Functions over Quadratic Extensions of Finite Fields
Creators: name: Chen, Ruikai
name: Mesnager, Sihem
Publisher: name: arXiv
Year: 2023
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: 11T06, 12E10, 51E15, 11R58, 11T06, 11T55, 14H05

description: Permutation rational functions over finite fields have attracted much attention in recent years. In this paper, we introduce a class of permutation rational functions over $\mathbb F_{q^2}$, whose numerators are so-called $q$-quadratic polynomials. To this end, we will first determine the exact number of zeros of a special $q$-quadratic polynomial in $\mathbb F_{q^2}$, by calculating character sums related to quadratic forms of $\mathbb F_{q^2}/\mathbb F_q$. Then given some rational function, we can demonstrate whether it induces a permutation of $\mathbb F_{q^2}$.
The hunt for interstellar phosphorus, the forgotten pre-biotic element
Creators: name: Fontani, Francesco
name: Rivilla, Victor M.
name: Mininni, Chiara
Publisher: name: Il Colle di Galileo
Year: 2019

description: Il fosforo è un elemento cruciale per lo sviluppo della vita come la conosciamo, ma a causa della sua bassa abbondanza cosmica, fino a pochi anni fa la sua chimica interstellare era quasi del tutto sconosciuta. Dal 2016, il gruppo di Formazione Stellare di Arcetri ha contribuito in modo fondamentale alla comprensione di alcuni processi astrochimici che coinvolgono questo elemento in regioni della Galassia in cui si formano nuove stelle, aprendo la strada a un numero crescente di studi su questo elemento pre-biotico finora “dimenticato”.
description: Il Colle di Galileo, Vol 8 No 1 (2019)
ZARZĄDZANIE FUNDUSZAMI EUROPEJSKIMI W POLSCE
Creators: name: Michał Piechowicz
Publisher: name: figshare
Year: 2018
Subjects: subject: 150301 Business Information Management (incl. Records, Knowledge and Information Management, and Intelligence)
subject: FOS: Economics and business

description: ZARZĄDZANIE FUNDUSZAMI EUROPEJSKIMI W POLSCEby Małgorzata Sikora-Gaca i Michal Piechowicz
Application of the path optimization method to a discrete spin system
Creators: name: Kashiwa, Kouji
name: Namekawa, Yusuke
name: Ohnishi, Akira
name: Takase, Hayato
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The path optimization method, which is proposed to control the sign problem in quantum field theories with continuous degrees of freedom by machine learning, is applied to a spin model with discrete degrees of freedom. The path optimization method is applied by replacing the spins with dynamical variables via the Hubbard-Stratonovich transformation, and the sum with the integral. The one-dimensional (Lenz-)Ising model with a complex coupling constant is used as a laboratory for the sign problem in the spin model. The average phase factor is enhanced by the path optimization method, indicating that the method can weaken the sign problem. Our result reproduces the analytic values with controlled statistical errors.
description: 8 pages, 5 figures, version accepted for publication in Phys. Rev. D
Exploring dengue proteome to design an effective epitope-based vaccine against dengue virus
Creators: name: Sabetian, Soudabeh
name: Nezafat, Navid
name: Hesam Dorosti
name: Mahboubeh Zarei
name: Ghasemi, Younes
Publisher: name: Taylor & Francis
Year: 2018
Subjects: subject: Medicine
subject: Microbiology
subject: FOS: Biological sciences
subject: Biotechnology
subject: Immunology
subject: FOS: Clinical medicine
subject: 69999 Biological Sciences not elsewhere classified
subject: Cancer
subject: 110309 Infectious Diseases
subject: FOS: Health sciences
subject: 60506 Virology

description: Dengue, a mosquito-borne disease, is caused by four known dengue serotypes. This infection causes a range of symptoms from a mild fever to a sever homorganic fever and death. It is a serious public health problem in subtropical and tropical countries. There is no specific vaccine currently available for clinical use and study on this issue is ongoing. In this study, bioinformatics approaches were used to predict antigenic, immunogenic, non-allergenic, and conserved B and T-cell epitopes as promising targets to design an effective peptide-based vaccine against dengue virus. Molecular docking analysis indicated the deep binding of the identified epitopes in the binding groove of the most popular human MHC I allele (human leukocyte antigens [HLA] A*0201). The final vaccine construct was created by conjugating the B and T-cell identified epitopes using proper linkers and adding an appropriate adjuvant at the N-terminal. The characteristics of the new subunit vaccine demonstrated that the epitope-based vaccine was antigenic, non-toxic, stable, and soluble. Other physicochemical properties of the new designed construct including isoelectric point value, aliphatic index, and grand average of hydropathicity were biologically considerable. Molecular docking of the engineered vaccine with Toll-like receptor 2 (TLR2) model revealed the hydrophobic interaction between the adjuvant and the ligand binding regions in the hydrophobic channel of TLR2. The study results indicated the high potential capability of the new multi-epitope vaccine to induce cellular and humoral immune responses against the dengue virus. Further experimental tests are required to investigate the immune protection capacity of the new vaccine construct in animal models. Communicated by Ramaswamy H. Sarma
QCD at finite isospin density
Creators: name: Son, D. T.
name: Stephanov, M. A.
Publisher: name: arXiv
Year: 2000
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Lattice (hep-lat)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: QCD at finite isospin chemical potential mu_I has no fermion sign problem and can be studied on the lattice. We solve this theory analytically in two limits: at low mu_I where chiral perturbation theory is applicable, and at asymptotically high mu_I where perturbative QCD works. At low isospin density the ground state is a pion condensate, whereas at high density it is a Fermi liquid with Cooper pairing. The pairs carry the same quantum numbers as the pion. This leads us to a conjecture that the transition from hadron to quark matter is smooth, which passes several tests. Our results imply a nontrivial phase diagram in the space of temperature and chemical potentials of isospin and baryon number.
description: 4 pages, 1 figure, version to appear in PRL
Un micro-oscillatore optomeccanico in una goccia
Creators: name: Gagliardi, Gianluca
Publisher: name: Il Colle di Galileo
Year: 2019

description: Un esperimento svolto presso la sezione di Napoli dell’Istituto Nazionale di Ottica (INO) del CNR ha mostrato la possibilità di eccitare onde di superficie su piccole gocce liquide per mezzo di un fascio luminoso. Il dispositivo così realizzato si comporta come un vero e proprio micro-oscillatore, costituito però interamente da liquido e mantenuto in forma sferica quasi perfetta dalla sola tensione superficiale.
description: Il Colle di Galileo, Vol 8 No 1 (2019)
Neural Texture Block Compression
Creators: name: Fujieda, Shin
name: Harada, Takahiro
Publisher: name: arXiv
Year: 2024
Subjects: subject: Image and Video Processing (eess.IV)
subject: Graphics (cs.GR)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: Block compression is a widely used technique to compress textures in real-time graphics applications, offering a reduction in storage size. However, their storage efficiency is constrained by the fixed compression ratio, which substantially increases storage size when hundreds of high-quality textures are required. In this paper, we propose a novel block texture compression method with neural networks, Neural Texture Block Compression (NTBC). NTBC learns the mapping from uncompressed textures to block-compressed textures, which allows for significantly reduced storage costs without any change in the shaders.Our experiments show that NTBC can achieve reasonable-quality results with up to about 70% less storage footprint, preserving real-time performance with a modest computational overhead at the texture loading phase in the graphics pipeline.
description: 16 pages, 13 figures
Calibration in Machine Learning Uncertainty Quantification: beyond consistency to target adaptivity
Creators: name: Pernot, Pascal
Publisher: name: arXiv
Year: 2023
Subjects: subject: Machine Learning (stat.ML)
subject: Machine Learning (cs.LG)
subject: Chemical Physics (physics.chem-ph)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: Reliable uncertainty quantification (UQ) in machine learning (ML) regression tasks is becoming the focus of many studies in materials and chemical science. It is now well understood that average calibration is insufficient, and most studies implement additional methods testing the conditional calibration with respect to uncertainty, i.e. consistency. Consistency is assessed mostly by so-called reliability diagrams. There exists however another way beyond average calibration, which is conditional calibration with respect to input features, i.e. adaptivity. In practice, adaptivity is the main concern of the final users of a ML-UQ method, seeking for the reliability of predictions and uncertainties for any point in features space. This article aims to show that consistency and adaptivity are complementary validation targets, and that a good consistency does not imply a good adaptivity. Adapted validation methods are proposed and illustrated on a representative example.
description: arXiv admin note: text overlap with arXiv:2303.07170
Power corrections to the photon polarization tensor in a hot and dense medium of massive fermions
Creators: name: Ferreira, Osvaldo
name: Fraga, Eduardo S.
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We compute the $\mathcal{O}(k^2)$ terms (power corrections) of the photon polarization tensor in a hot and dense medium of particles with a small but finite mass, i.e., $0< m\ll T, μ$. We perform our calculations within the hard thermal loop approximation in the real-time formalism, and evaluate the first nonzero mass corrections. For a renormalization scale $\barΛ\sim T$, these mass contributions determine the temperature dependence of the power corrections. These results have direct implications in the computation of electric and magnetic susceptibilities of hot and dense media in equilibrium. We address such implications and make comparisons with previous results.
description: 10 pages, 2 figure. Additional section included in this version. Matches the published version
Dimensional Reduction
Creators: name: Manogue, Corinne A.
name: Dray, Tevian
Publisher: name: arXiv
Year: 1998
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Using an octonionic formalism, we introduce a new mechanism for reducing 10 spacetime dimensions to 4 without compactification. Applying this mechanism to the free, 10-dimensional, massless (momentum space) Dirac equation results in a particle spectrum consisting of exactly 3 generations. Each generation contains 1 massive spin-1/2 particle with 2 spin states, 1 massless spin-1/2 particle with only 1 helicity state, and their antiparticles --- precisely one generation of leptons. There is also a single massless spin-1/2 particle/antiparticle pair with the opposite helicity and no generation structure. We conclude with a discussion of some further consequences of this approach, including those which could arise when using the formalism on a curved spacetime background, as well as the implications for the nature of spacetime itself.
description: Honorable Mention, 1998 Gravity Research Foundation essay contest (REVTeX, 3 pages)
Artificial intelligence and machine learning applications for cultured meat
Creators: name: Todhunter, Michael E.
name: Jubair, Sheikh
name: Verma, Ruchika
name: Saqe, Rikard
name: Shen, Kevin
name: Duffy, Breanna
Publisher: name: arXiv
Year: 2024
Subjects: subject: Computers and Society (cs.CY)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: Cultured meat has the potential to provide a complementary meat industry with reduced environmental, ethical, and health impacts. However, major technological challenges remain which require time- and resource-intensive research and development efforts. Machine learning has the potential to accelerate cultured meat technology by streamlining experiments, predicting optimal results, and reducing experimentation time and resources. However, the use of machine learning in cultured meat is in its infancy. This review covers the work available to date on the use of machine learning in cultured meat and explores future possibilities. We address four major areas of cultured meat research and development: establishing cell lines, cell culture media design, microscopy and image analysis, and bioprocessing and food processing optimization. This review aims to provide the foundation necessary for both cultured meat and machine learning scientists to identify research opportunities at the intersection between cultured meat and machine learning.
description: 23 pages (43 pages with references), 4 figures. The first two listed authors share first authorship; they and the last listed author contributed equally to this work
Stochastic Acceleration of Low Energy Electrons in Plasmas with Finite Temperature
Creators: name: Pryadko, Julia
name: Petrosian, Vahe
Publisher: name: arXiv
Year: 1997
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: This paper extends our earlier work on the acceleration of low-energy electrons by plasma turbulence to include the effects of finite temperature of the plasma. We consider the resonant interaction of thermal electrons with the whole transverse branch of plasma waves propagating along the magnetic field. We show that our earlier published results for acceleration of low-energy electrons can be applied to the case of finite temperature if a sufficient level of turbulence is present. From comparison of the acceleration rate of the thermal particles with the decay rate of the waves with which they interact, we determine the required energy density of the waves as a fraction of the magnetic energy density, so that a substantial fraction of the background plasma electrons can be accelerated. The dependence of this value on the plasma parameter alpha = omega_pe / Omega_e (the ratio of electron plasma frequency to electron gyrofrequency), plasma temperature, and turbulence spectral parameters is quantified. We show that the result is most sensitive to the plasma parameter alpha. We estimate the required level of total turbulence by calculating the level of turbulence required for the initial acceleration of thermal electrons and that required for further acceleration to higher energies.
Full counting statistics of the two-stage Kondo effect
Creators: name: Karki, D. B.
name: Kiselev, Mikhail N.
Publisher: name: arXiv
Year: 2018
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We developed a theoretical framework which extends the method of \textit{full counting statistics} (FCS) from conventional single channel Kondo screening schemes to multi-channel Kondo paradigm. The developed idea of FCS has been demonstrated considering an example of two-stage Kondo (2SK) model. We analyzed the charge transferred statistics in the strong-coupling regime of a 2SK model using non-equilibrium Keldysh formulation. A bounded value of Fano factor, $1\leq F\leq 5/3$, confirmed the cross-over regimes of charge transfered statistics in 2SK effect, from Poissonian to super-Poissonian. An innovative way of measuring transport properties of 2SK effect, by the independent measurements of charge current and noise, has been proposed
description: 10 pages with 5 figures (Published version)
Tidal Dissipation in Evolved Low and Intermediate Mass Stars
Creators: name: Esseldeurs, M.
name: Mathis, S.
name: Decin, L.
Publisher: name: arXiv
Year: 2024
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: As the observed occurrence for planets or stellar companions orbiting low and intermediate-mass evolved stars is increasing, so does the importance of understanding and evaluating the strength of their interactions. One of the fundamental mechanisms to understand this interaction is the tidal dissipation in these stars, as it is one of the engines of orbital/rotational evolution of star-planet/star-star systems. This article builds on previous works studying the evolution of the tidal dissipation along the pre-MS and the MS, which have shown the strong link between the structural and rotational evolution of stars and tidal dissipation. This article provides for the first time a complete picture of tidal dissipation along the entire evolution of low and intermediate-mass stars, including the advanced phases of evolution. Using stellar evolutionary models, the internal structure of the star is computed from the pre-MS all the way up to the white dwarf phase, for stars with initial mass between 1 and 4 Msun. Tidal dissipation is separated into two components: the dissipation of the equilibrium (non-wavelike) tide and the dissipation of the dynamical (wavelike) tide. For evolved stars the dynamical tide is constituted by progressive internal gravity waves. The significance of both the equilibrium and dynamical tide dissipation becomes apparent within distinct domains of the parameter space. The dissipation of the equilibrium tide is dominant when the star is large in size or the companion is far away from the star. Conversely the dissipation of the dynamical tide is important when the star is small in size or the companion is close to the star. Both the equilibrium and the dynamical tides are important in evolved stars, and therefore both need to be taken into account when studying the tidal dissipation in evolved stars and the evolution of planetary or/and stellar companions orbiting them.
Polarization of Prompt J/psi at the Tevatron
Creators: name: Braaten, Eric
name: Kniehl, Bernd A.
name: Lee, Jungil
Publisher: name: arXiv
Year: 1999
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The polarization of prompt J/psi at the Fermilab Tevatron is calculated within the nonrelativistic QCD factorization framework. The contribution from radiative decays of P-wave charmonium states decreases, but does not eliminate, the transverse polarization at large transverse momentum. The angular distribution parameter alpha for leptonic decays of the J/ψis predicted to increase from near 0 at p_T = 5 GeV to about 0.5 at p_T = 20 GeV. The prediction is consistent with measurements by the CDF Collaboration at intermediate values of p_T, but disagrees by about 3 standard deviations at the largest values of p_T measured.
description: 4 pages, 2 figures, one reference added, accepted for publication in Phys. Rev. D
The use of new media in the European Commission's information policy
Creators: name: Michał Piechowicz
Publisher: name: figshare
Year: 2018
Subjects: subject: 190205 Interactive Media
subject: FOS: Arts (arts, history of arts, performing arts, music)

description: Przegląd Europejski, 2016Recent years confirm that new media have become one of the basic elements of creating communication strategies for the EU institutions. Officials and main decision-makers are increasingly involved in the realm of social media. It is even more significant when we observe that they make use of this tools in a fully transparent way. Such activities add new dynamics to European communication policy. This paper discusses the real-time nature of the Internet communication sphere of the EU institutions created within the guidelines of the European Commission’s new communication strategy, which makes social media complementary to conventional informational operations.
Vortex Lattices in Active Nematics with Periodic Obstacle Arrays
Creators: name: Schimming, Cody D.
name: Reichhardt, C. J. O.
name: Reichhardt, C.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We numerically model a two-dimensional active nematic confined by a periodic array of fixed obstacles. Even in the passive nematic, the appearance of topological defects is unavoidable due to planar anchoring by the obstacle surfaces. We show that a vortex lattice state emerges as activity is increased, and that this lattice may be tuned from ``ferromagnetic'' to ``antiferromagnetic'' by varying the gap size between obstacles. We map the rich variety of states exhibited by the system as a function of distance between obstacles and activity, including a pinned defect state, motile defects, the vortex lattice, and active turbulence. We demonstrate that the flows in the active turbulent phase can be tuned by the presence of obstacles, and explore the effects of a frustrated lattice geometry on the vortex lattice phase.
description: 6 + 8 pages, 4 + 3 figures
Thermalization and localization of an oscillating Bose-Einstein condensate in a disordered trap
Creators: name: Hsueh, Che-Hsiu
name: Ong, Russell
name: Tseng, Jing-Fu
name: Tsubota, Makoto
name: Wu, Wen-Chin
Publisher: name: arXiv
Year: 2018
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: We numerically simulate an oscillating Bose-Einstein condensate in a disordered trap [Phys. Rev. A 82, 033603 (2010)] and the results are in good agreement with the experiment. It allows us to verify that total energy and particle number are conserved in this quantum system. The disorder acts as a medium, which results in a relaxation from nonequilibrium to equilibrium, i.e., thermalization. An algebraic localization is realized when the system approaches the equilibrium, and if the system falls into the regime when the healing length of the condensate exceeds the correlation length of the disorder, exponential Anderson localization is to be observed.
description: 5 pages, 4 figures
Displaced vertex signatures of doubly charged scalars in the type-II seesaw and its left-right extensions
Creators: name: Dev, P. S. Bhupal
name: Zhang, Yongchao
Publisher: name: arXiv
Year: 2018
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: The type-II seesaw mechanism with an isospin-triplet scalar $Δ_L$ provides one of the most compelling explanations for the observed smallness of neutrino masses. The triplet contains a doubly-charged component $H_L^{\pm\pm}$, which dominantly decays to either same-sign dileptons or to a pair of $W$ bosons, depending on the size of the triplet vacuum expectation value. However, there exists a range of Yukawa couplings $f_L$ of the triplet to the charged leptons, wherein a relatively light $H_L^{\pm\pm}$ tends to be long-lived, giving rise to distinct displaced-vertex signatures at the high-energy colliders. We find that the displaced vertex signals from the leptonic decays $H_L^{\pm\pm} \to \ell_α^\pm \ell_β^\pm$ could probe a broad parameter space with $10^{-10} \lesssim |f_L| \lesssim 10^{-6}$ and 45.6 GeV $< M_{H_L^{\pm\pm}} \lesssim 200$ GeV at the high-luminosity LHC. Similar sensitivity can also be achieved at a future 1 TeV $e^+e^-$ collider. The mass reach can be extended to about 500 GeV at a future 100 TeV proton-proton collider. Similar conclusions apply for the right-handed triplet $H_R^{\pm\pm}$ in the TeV-scale left-right symmetric models, which provide a natural embedding of the type-II seesaw. We show that the displaced vertex signals are largely complementary to the prompt same-sign dilepton pair searches at the LHC and the low-energy, high-intensity/precision measurements, such as neutrinoless double beta decay, charged lepton flavor violation, electron and muon anomalous magnetic moments, muonium oscillation and Møller scattering.
description: 49 pages, 25 figures and 2 tables, minor changes, version to appear in JHEP
Uncertainty Quantification of Autoencoder-based Koopman Operator
Creators: name: Kim, Jin Sung
name: Quan, Ying Shuai
name: Chung, Chung Choo
Publisher: name: arXiv
Year: 2023
Subjects: subject: Systems and Control (eess.SY)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: This paper proposes a method for uncertainty quantification of an autoencoder-based Koopman operator. The main challenge of using the Koopman operator is to design the basis functions for lifting the state. To this end, this paper builds an autoencoder to automatically search the optimal lifting basis functions with a given loss function. We approximate the Koopman operator in a finite-dimensional space with the autoencoder, while the approximated Koopman has an approximation uncertainty. To resolve the problem, we compute a robust positively invariant set for the approximated Koopman operator to consider the approximation error. Then, the decoder of the autoencoder is analyzed by robustness certification against approximation error using the Lipschitz constant in the reconstruction phase. The forced Van der Pol model is used to show the validity of the proposed method. From the numerical simulation results, we confirmed that the trajectory of the true state stays in the uncertainty set centered by the reconstructed state.
description: 6 pages, 3 figures
On-Device Training of Fully Quantized Deep Neural Networks on Cortex-M Microcontrollers
Creators: name: Deutel, Mark
name: Hannig, Frank
name: Mutschler, Christopher
name: Teich, Jürgen
Publisher: name: arXiv
Year: 2024
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: On-device training of DNNs allows models to adapt and fine-tune to newly collected data or changing domains while deployed on microcontroller units (MCUs). However, DNN training is a resource-intensive task, making the implementation and execution of DNN training algorithms on MCUs challenging due to low processor speeds, constrained throughput, limited floating-point support, and memory constraints. In this work, we explore on-device training of DNNs for Cortex-M MCUs. We present a method that enables efficient training of DNNs completely in place on the MCU using fully quantized training (FQT) and dynamic partial gradient updates. We demonstrate the feasibility of our approach on multiple vision and time-series datasets and provide insights into the tradeoff between training accuracy, memory overhead, energy, and latency on real hardware.
description: 12 pages, 9 figures