cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Angular resolved electron energy loss spectroscopy in hexagonal boron nitride
Creators: name: Fossard, Frédéric
name: Sponza, Lorenzo
name: Schué, Léonard
name: Attaccalite, Claudio
name: Ducastelle, François
name: Barjon, Julien
name: Loiseau, Annick
Publisher: name: arXiv
Year: 2017
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Electron energy loss spectra have been measured on hexagonal boron nitride single crystals employing a novel electron energy loss spectroscopic set-up composed by an electron microscope equipped with a monochromator and an in-column filter. This set-up provides high-quality energy-loss spectra and allows also for the imaging of energy-filtered diffraction patterns. These two acquisition modes provide complementary pieces of information, offering a global view of excitations in reciprocal space. As an example of the capabilities of the method we show how easily the core loss spectra at the $K$ edges of boron and nitrogen can be measured and imaged. Low losses associated to interband and/or plasmon excitations are also measured. This energy range allows us to illustrate that our method provides results of quality comparable to those obtained from non resonant X-ray inelastic scattering, but with advantageous specificities such as an enhanced sensitivity at low q and a much higher simplicity and versatility that makes it well adapted to the study of two-dimensional materials and related heterostructures. Finally, by comparing theoretical calculations against our measures, we are able to relate the range of applicability of ab initio calculations to the anisotropy of the sample and assess the level of approximation required for a proper simulation of our acquisition method.
Adaptive mesh selection asymptotically guarantees a prescribed local error for systems of initial value problems
Creators: name: Kacewicz, Boleslaw
Publisher: name: arXiv
Year: 2017
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics
subject: 65L05, 65L50, 65L70

description: We study adaptive mesh selection for the solution of systems of initial value problems. The goal is a rigorous theoretical analysis of potential advantages of adaption. For an optimal method in the sense of the speed of convergence, we propose an algorithm for successive selection of the mesh points. The selection is based on an upper bound on the local error, and it (asymptotically) guarantees the local errors not exceeding a prescribed level. The mesh selection algorithm can be applied to a general class of methods, not only to the chosen one. We rigorously discuss the cost of the proposed algorithm, comparing it to other algorithms equipped with different mesh selection procedures. We specify a quantitative advantage of the adaptive mesh over the uniform one. Adjustment of the mesh points to a local behavior of the solution yields improved efficiency of the algorithm. Some numerical results illustrating theoretical findings are reported.
description: 24 pages, minor revision, to appear in Advances in Computational Mathematics
A conjecture on $C$-matrices of cluster algebras
Creators: name: Cao, Peigen
name: Huang, Min
name: Li, Fang
Publisher: name: arXiv
Year: 2017
Subjects: subject: Rings and Algebras (math.RA)
subject: Commutative Algebra (math.AC)
subject: Representation Theory (math.RT)
subject: FOS: Mathematics
subject: 13F60

description: For a skew-symmetrizable cluster algebra $\mathcal A_{t_0}$ with principal coefficients at $t_0$, we prove that each seed $Σ_t$ of $\mathcal A_{t_0}$ is uniquely determined by its {\bf C-matrix}, which was proposed by Fomin and Zelevinsky in \cite{FZ3} as a conjecture. Our proof is based on the fact that the positivity of cluster variables and sign-coherence of $c$-vectors hold for $\mathcal A_{t_0}$, which was actually verified in \cite{GHKK}. More discussion is given in the sign-skew-symmetric case so as to obtain a conclusion as weak version of the conjecture in this general case.
description: 7 pages
title: Timescales of magmatism in the Eifel (Germany), from crustal growth to Quaternary volcanism - A xenolith perspective
Creators: name: Sturm, Anne
name: Schmitt, Axel
Publisher: name: Deutsche Geologische Gesellschaft - Geologische Vereinigung e.V. (DGGV)
Year: 2022

description:
Xenoliths transported to the surface by ascending magmas are crucial to decipher the structure and composition of the Earth’s crust and provide valuable insights into melt formation and magma storage conditions. This cross-crustal sampling is of particular importance in regions where no basement outcrops exist, such as the Eifel, Germany. Crustal xenoliths containing zircon are suitable targets for U/Pb geochronology to quantify the timing of intra-crustal magmatic and metamorphic events.

The Quaternary Eifel volcanic field consist of >300 volcanoes including maars, scoria cones and tuff rings. Precise eruption ages for these are rare and often inconsistent between the different methods. A promising approach to determine accurate eruption ages is to apply (U-Th)/He geochronology to zircon extracted from partially re-melted crustal xenoliths embedded in pyroclastic material.

So far, we collected >200 xenoliths from >35 volcanoes in the West- and East Eifel. We observe significant differences in xenolith abundance between the volcanic centers and a variety of xenolith types, including magmatic and metamorphic rocks with varying degrees of pyrometamorphic overprinting. Zircon crystallization ages range from ca. 2000 to 280 Ma, clustering around Variscan and Caledonian ages. Remarkably, the youngest U/Pb ages indicate post-Variscan plutonic magmatism reaching to the Permian, which has not yet been reported for this area.

Preliminary (U-Th)/He zircon eruption ages acquired for the Meerfeld and Gemünden Maar confirm the feasibility of the method. Future work on xenolith samples from additional centers will generate a comprehensive dataset of eruption ages to unravel the spatiotemporal evolution of the Eifel volcanic field.
Linking axionlike dark matter to neutrino masses
Creators: name: Carvajal, C. D. R.
name: Sánchez-Vega, B. L.
name: Zapata, O.
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We present a framework linking axionlike particles (ALPs) to neutrino masses through the minimal inverse seesaw (ISS) mechanism in order to explain the dark matter (DM) puzzle. Specifically, we explore three minimal ISS cases where mass scales are generated through gravity-induced operators involving a scalar field hosting ALPs. In all of these cases, we find gravity-stable models providing the observed DM relic density and, simultaneously, consistent with the phenomenology of neutrinos and ALPs. Remarkably, in one of the ISS cases, the DM can be made of ALPs and sterile neutrinos. Furthermore, other considered ISS cases have ALPs with parameters inside regions to be explored by proposed ALPs experiments.
description: 1 figure, 14 pages
The origin of fine structure in magnetization curve of $α$-CoV$_2$O$_6$
Creators: name: Kudasov, Yu. B.
name: Kozabaranov, R. V.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences
subject: 82B20

description: Multiple field-induced plateaus in $α$-CoV$_2$O$_6$ at low temperatures were revealed earlier by M. Lenertz et al. [J. Phys. Chem. C 115, 17190 (2011)] and carefully investigated recently by M. Nandi and P. Mandal [J. Appl. Phys. 119, 133904 (2016)]. Four equidistant steps were observed in the magnetization curve. We present a model to describe this phenomenon. A magnetic structure of this substance is formed by highly anisotropic triangular lattice of Ising chains running along the $\bf{b}$ axis. Due to a three-fold degeneracy of three-sublattice magnetic ordering, domain boundaries appear. Their transformation under magnetic field variation leads to two additional steps in the 1/3 magnetization plateau and gives rise to complex magnetic behavior observed experimentally. The domain structure in $α$-CoV$_2$O$_6$ occurs to be strongly anisotropic because a lifetime of the metastable states depends greatly on the configuration orientation. A strong dependence of the magnetization curve on magnetic field sweep time is predicted.
description: 4 pages, 5 figures, presented at Moscow International Simposium on Magnetism 2017, submitted to EPJ: Conf
Some asymptotic results for nonlinear Hawkes processes
Creators: name: Gao, Fuqing
name: Zhu, Lingjiong
Publisher: name: arXiv
Year: 2017
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics

description: Hawkes process is a class of simple point processes with self-exciting and clustering properties. Hawkes process has been widely applied in finance, neuroscience, social networks, criminology, seismology, and many other fields. In this paper, we study fluctuations, large deviations and moderate deviations nonlinear Hawkes processes in a new asymptotic regime, the large intensity function and the small exciting function regime. It corresponds to the large baseline intensity asymptotics for the linear case, and can also be interpreted as the asymptotics for the mean process of Hawkes processes on a large network.
description: 33 pages
Parabolic equations with singular divergence-free drift vector fields
Creators: name: Qian, Zhongmin
name: Xi, Guangyu
Publisher: name: arXiv
Year: 2016
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: In this paper, we study an elliptic operator in divergence-form but not necessary symmetric. In particular, our results can be applied to elliptic operator $L=νΔ+u(x,t)\cdot\nabla$, where $u(\cdot,t)$ is a time-dependent vector field in $\mathbb{R}^{n}$, which is divergence-free in distribution sense, i.e. $\nabla\cdot u=0$. Suppose $u\in L_{t}^{\infty}(\textrm{BMO}_{x}^{-1})$. We show the existence of the fundamental solution $\varGamma(x,t;ξ,τ)$ of the parabolic operator $L-\partial_{t}$, and show that $\varGamma$ satisfies the Aronson estimate with a constant depending only on the dimension $n$, the elliptic constant $ν$ and the norm $\left\Vert u\right\Vert _{L^{\infty}(\textrm{BMO}^{-1})}$. Therefore the existence and uniqueness of the parabolic equation $\left(L-\partial_{t}\right)v=0$ are established for initial data in $L^{2}$-space, and their regularity is obtained too. In fact, we establish these results for a general non-symmetric elliptic operator in divergence form.
description: 28 pages
Source localization in an ocean waveguide using supervised machine learning
Creators: name: Niu, Haiqiang
name: Reeves, Emma
name: Gerstoft, Peter
Publisher: name: arXiv
Year: 2017
Subjects: subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: Neural and Evolutionary Computing (cs.NE)
subject: Geophysics (physics.geo-ph)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Source localization in ocean acoustics is posed as a machine learning problem in which data-driven methods learn source ranges directly from observed acoustic data. The pressure received by a vertical linear array is preprocessed by constructing a normalized sample covariance matrix (SCM) and used as the input. Three machine learning methods (feed-forward neural networks (FNN), support vector machines (SVM) and random forests (RF)) are investigated in this paper, with focus on the FNN. The range estimation problem is solved both as a classification problem and as a regression problem by these three machine learning algorithms. The results of range estimation for the Noise09 experiment are compared for FNN, SVM, RF and conventional matched-field processing and demonstrate the potential of machine learning for underwater source localization..
description: Submitted to The Journal of the Acoustical Society of America
A high-resolution programmable Vernier delay generator based on carry chains in FPGA
Creators: name: Cui, Ke
name: Li, Xiangyu
name: Zhu, Rihong
Publisher: name: arXiv
Year: 2017
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: This paper presents an architecture of high-resolution delay generator implemented in a single field programmable gate array (FPGA) chip by exploiting the method of utilizing dedicated carry chains. It serves as the core component in various physical instruments. The proposed delay generator contains the coarse delay step and the fine delay step to guarantee both large dynamic range and high resolution. The carry chains are organized in the Vernier delay loop style to fulfill the fine delay step with high precision and high linearity. The delay generator was implemented in the EP3SE110F1152I3 Stratix III device from Altera on a self-designed test board. Test results show the obtained resolution is 38.6 ps, and the differential nonlinearity (DNL) and integral nonlinearity (INL) is in the range of (-0.18 least significant bit (LSB),0.24 LSB)\(-0.02 LSB,0.01 LSB) under the nominal supply voltage of 1100 mV and environmental temperature of 20 degrees centigrade. The delay generator is also rather resource cost efficient which uses only 668 LUTs and 146 registers in total.
description: 7 pages, 10 figures; published on Review of Scientific Instruments
Penetration of fast projectiles into resistant media: from macroscopic to subatomic projectiles
Creators: name: Gaite, Jose
Publisher: name: arXiv
Year: 2017
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Classical Physics (physics.class-ph)
subject: FOS: Physical sciences

description: The penetration of a fast projectile into a resistant medium is a complex process that is suitable for simple modeling, in which basic physical principles can be profitably employed. This study connects two different domains: the fast motion of macroscopic bodies in resistant media and the interaction of charged subatomic particles with matter at high energies, which furnish the two limit cases of the problem of penetrating projectiles of different sizes. These limit cases actually have overlapping applications; for example, in space physics and technology. The intermediate or mesoscopic domain finds application in atom cluster implantation technology. Here it is shown that the penetration of fast nano-projectiles is ruled by a slightly modified Newton's inertial quadratic force, namely, $F \sim v^{2-β}$, where $β$ vanishes as the inverse of projectile diameter. Factors essential to penetration depth are ratio of projectile to medium density and projectile shape.
description: 15 pages, Revtex; updated NASA link, corrected minor error in page 4
Direct observation of spin-quadrupolar excitations in Sr$_2$CoGe$_2$O$_7$ by high field ESR
Creators: name: Akaki, Mitsuru
name: Yoshizawa, Daichi
name: Okutani, Akira
name: Kida, Takanori
name: Romhányi, Judit
name: Penc, Karlo
name: Hagiwara, Masayuki
Publisher: name: arXiv
Year: 2017
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Exotic spin-multipolar ordering in spin transition metal insulators has so far eluded unambiguous experimental observation. A less studied, but perhaps more feasible fingerprint of multipole character emerges in the excitation spectrum in the form of quadrupolar transitions. Such multipolar excitations are desirable as they can be manipulated with the use of light or electric field and can be captured by means of conventional experimental techniques. Here we study single crystals of multiferroic Sr$_2$CoGe$_2$O$_7$, and show that due to its nearly isotropic nature a purely quadrupolar bimagnon mode appears in the electron spin resonance (ESR) spectra. This non-magnetic spin-excitation couples to the electric field of the light and becomes observable for a specific experimental configuration, in full agreement with a theoretical analysis of the selection rules.
description: 19 pages, 13 figures, , accepted for publication in Phys. Rev. B
Anyons are not energy eigenspaces of quantum double Hamiltonians
Creators: name: Komar, Anna
name: Landon-Cardinal, Olivier
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Physics (quant-ph)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Kitaev's quantum double models, including the toric code, are canonical examples of quantum topological models on a 2D spin lattice. Their Hamiltonian defines the groundspace by imposing an energy penalty to any nontrivial flux or charge, but does not distinguish among those. We generalize this construction by introducing a novel family of Hamiltonians made of commuting four-body projectors that provide an intricate splitting of the Hilbert space by discriminating among non-trivial charges and fluxes. Our construction highlights that anyons are not in one-to-one correspondence with energy eigenspaces, a feature already present in Kitaev's construction. This discrepancy is due to the presence of local degrees of freedom in addition to topological ones on a lattice.
description: 18 pages, 8 figures. Added Sec.V and Fig. 7 to clarify "charge flavors"; modififed title
Discontinuous classical ground state magnetic response as an even-odd effect in higher order rotationally invariant exchange interactions
Creators: name: Konstantinidis, N. P.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The classical ground state magnetic response of the Heisenberg model when rotationally invariant exchange interactions of integer order q>1 are added is found to be discontinuous, even though the interactions lack magnetic anisotropy. This holds even in the case of bipartite lattices which are not frustrated, as well as for the frustrated triangular lattice. The total number of discontinuities is associated with even-odd effects as it depends on the parity of q via the relative strength of the bilinear and higher order exchange interactions, and increases with q. These results demonstrate that the precise form of the microscopic interactions is important for the ground state magnetization response.
description: 10 pages, 8 figures, 8 tables
Age-dating Luminous Red Galaxies observed with the Southern African Large Telescope
Creators: name: Ratsimbazafy, A. L.
name: Loubser, S. I.
name: Crawford, S. M.
name: Cress, C. M.
name: Bassett, B. A.
name: Nichol, R. C.
name: Väisänen, P.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We measure a value for the cosmic expansion of $H(z) = 89 \pm 23$(stat) $\pm$ 44(syst) km s$^{-1}$ Mpc$^{-1}$ at a redshift of $z \simeq 0.47$ based on the differential age technique. This technique, also known as cosmic chronometers, uses the age difference between two redshifts for a passively evolving population of galaxies to calculate the expansion rate of the Universe. Our measurement is based on analysis of high quality spectra of Luminous Red Galaxies (LRGs) obtained with the Southern African Large Telescope (SALT) in two narrow redshift ranges of $z \simeq 0.40$ and $z \simeq 0.55$ as part of an initial pilot study. Ages were estimated by fitting single stellar population models to the observed spectra. This measurement presents one of the best estimates of $H(z)$ via this method at $z\sim0.5$ to date.
description: 16 pages, 7 figures, 5 tables, fixed typos on H(z) values for figure 4, also for section 4
Inter-band Coherence Response to Electric Fields in Crystals
Creators: name: Culcer, Dimitrie
name: Sekine, Akihiko
name: MacDonald, Allan H.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: In solid state conductors, linear response to a steady electric field is normally dominated by Bloch state occupation number changes that are correlated with group velocity and lead to a steady state current. However, for a number of important physical observables, the most important response even in conductors can be electric-field induced coherence between Bloch states in different bands, such as that responsible for screening in dielectrics. Examples include the anomalous and spin-Hall effects, spin torques, minimum conductivities and the chiral anomaly. In this paper we present a general quantum kinetic theory of linear response to an electric field which can be applied to solids with arbitrarily complicated band structures and includes the inter-band coherence response and the Bloch-state repopulation responses on an equal footing. We aim to enable extensive transport theory applications using computational packages based on maximally localized Wannier functions. The formalism is based on density-matrix equations of motion, on a Born approximation treatment of disorder, and on an expansion in scattering rate to leading non-trivial order. The quasiparticle bands are treated in a completely general manner that allows for arbitrary forms of the spin-orbit interaction and for the broken time reversal symmetry of magnetic conductors. We demonstrate that the inter-band response in conductors consists primarily of two terms: an intrinsic contribution due to the entire Fermi sea that captures the Berry curvature contribution to wave-packet dynamics, and an anomalous contribution caused by scattering that is sensitive to the presence of the Fermi surface. We solve for some electric-field response properties of simple model systems that are known to be dominated by interband coherence contributions and discuss an extensive list of complicated problems that cannot be solved analytically.
Implementing the sine transform of fermionic modes as a tensor network
Creators: name: Epple, Hannes
name: Fries, Pascal
name: Hinrichsen, Haye
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Based on the algebraic theory of signal processing, we recursively decompose the discrete sine transform of first kind (DST-I) into small orthogonal block operations. Using a diagrammatic language, we then second-quantize this decomposition to construct a tensor network implementing the DST-I for fermionic modes on a lattice. The complexity of the resulting network is shown to scale as $\frac 54 n \log n$ (not considering swap gates), where $n$ is the number of lattice sites. Our method provides a systematic approach of generalizing Ferris' spectral tensor network for non-trivial boundary conditions.
description: 11 pages, 5 captioned figures
The isotensor axial polarisability and lattice QCD input for nuclear double-$β$ decay phenomenology
Creators: name: Shanahan, Phiala E.
name: Tiburzi, Brian C.
name: Wagman, Michael L.
name: Winter, Frank
name: Chang, Emmanuel
name: Davoudi, Zohreh
name: Detmold, William
name: Orginos, Kostas
name: Savage, Martin J.
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: The potential importance of short-distance nuclear effects in double-$β$ decay is assessed using a lattice QCD calculation of the $nn\rightarrow pp$ transition and effective field theory methods. At the unphysical quark masses used in the numerical computation, these effects, encoded in the isotensor axial polarisability, are found to be of similar magnitude to the nuclear modification of the single axial current, which phenomenologically is the quenching of the axial charge used in nuclear many-body calculations. This finding suggests that nuclear models for neutrinoful and neutrinoless double-$β$ decays should incorporate this previously neglected contribution if they are to provide reliable guidance for next-generation neutrinoless double-$β$ decay searches. The prospects of constraining the isotensor axial polarisabilities of nuclei using lattice QCD input into nuclear many-body calculations are discussed.
description: published version
Cavity assisted measurements of heat and work in optical lattices
Creators: name: Villa, Louis
name: De Chiara, Gabriele
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Physics (quant-ph)
subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: We propose a method to experimentally measure the internal energy of a system of ultracold atoms trapped in optical lattices by coupling them to the fields of two optical cavities. We show that the tunnelling and self-interaction terms of the one-dimensional Bose-Hubbard Hamiltonian can be mapped to the field and photon number of each cavity, respectively. We compare the energy estimated using this method with numerical results obtained using the density matrix renormalisation group algorithm. Our method can be employed for the assessment of power and efficiency of thermal machines whose working substance is a strongly correlated many-body system.
description: Accepted version in Quantum. Updates: New results for the work in quenching a Bose-Hubbard model; new references; v3 fixed doi links in references to make paper compliant with Quantum
Expectation values of twist fields and universal entanglement saturation of the free massive boson
Creators: name: Blondeau-Fournier, Olivier
name: Doyon, Benjamin
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The evaluation of vacuum expectation values (VEVs) in massive integrable quantum field theory (QFT) is a nontrivial renormalization-group "connection problem" -- relating large and short distance asymptotics -- and is in general unsolved. This is particularly relevant in the context of entanglement entropy, where VEVs of branch-point twist fields give universal saturation predictions. We propose a new method to compute VEVs of twist fields associated to continuous symmetries in QFT. The method is based on a differential equation in the continuous symmetry parameter, and gives VEVs as infinite form-factor series which truncate at two-particle level in free QFT. We verify the method by studying U(1) twist fields in free models, which are simply related to the branch-point twist fields. We provide the first exact formulae for the VEVs of such fields in the massive uncompactified free boson model, checking against an independent calculation based on angular quantization. We show that logarithmic terms, overlooked in the original work of Callan and Wilczek [Phys. Lett. B333 (1994)], appear both in the massless and in the massive situations. This implies that, in agreement with numerical form-factor observations by Bianchini and Castro-Alvaredo [Nucl. Phys. B913 (2016)], the standard power-law short-distance behavior is corrected by a logarithmic factor. We discuss how this gives universal formulae for the saturation of entanglement entropy of a single interval in near-critical harmonic chains, including log log corrections.
description: V2: 37 pages, explications and references added
Optically driven ultra-stable nanomechanical rotor
Creators: name: Kuhn, Stefan
name: Stickler, Benjamin A.
name: Kosloff, Alon
name: Patolsky, Fernando
name: Hornberger, Klaus
name: Arndt, Markus
name: Millen, James
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Physics (quant-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Nanomechanical devices have attracted the interest of a growing interdisciplinary research community, since they can be used as highly sensitive transducers for various physical quantities. Exquisite control over these systems facilitates experiments on the foundations of physics. Here, we demonstrate that an optically trapped silicon nanorod, set into rotation at MHz frequencies, can be locked to an external clock, transducing the properties of the time standard to the rod's motion with the remarkable frequency stability $f_{\rm r}/Δf_{\rm r}$ of $7.7 \times 10^{11}$. While the dynamics of this periodically driven rotor generally can be chaotic, we derive and verify that stable limit cycles exist over a surprisingly wide parameter range. This robustness should enable, in principle, measurements of external torques with sensitivities better than 0.25zNm, even at room temperature. We show that in a dilute gas, real-time phase measurements on the locked nanorod transduce pressure values with a sensitivity of 0.3%.
description: 5 pages, 4 figures
CMB Spectral Distortion Constraints on Thermal Inflation
Creators: name: Cho, Kihyun
name: Hong, Sungwook E.
name: Stewart, Ewan D.
name: Zoe, Heeseung
Publisher: name: arXiv
Year: 2017
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Thermal inflation is a second epoch of exponential expansion at typical energy scales $V^{1/4} \sim 10^{6 \sim 8} \mathrm{GeV}$. If the usual primordial inflation is followed by thermal inflation, the primordial power spectrum is only modestly redshifted on large scales, but strongly suppressed on scales smaller than the horizon size at the beginning of thermal inflation, $k > k_{\rm b} = a_{\rm b} H_{\rm b}$. We calculate the spectral distortion of the cosmic microwave background generated by the dissipation of acoustic waves in this context. For $k_{\rm b} \ll 10^3 \mathrm{Mpc}^{-1}$, thermal inflation results in a large suppression of the $μ$-distortion amplitude, predicting that it falls well below the standard value of $μ\simeq 2\times 10^{-8}$. Thus, future spectral distortion experiments, similar to PIXIE, can place new limits on the thermal inflation scenario, constraining $k_{\rm b} \gtrsim 10^3 \mathrm{Mpc}^{-1}$ if $μ\simeq 2\times 10^{-8}$ were found.
description: 18 pages, 7 figures
Higgs boson pair productions in the Georgi-Machacek model at the LHC
Creators: name: Chang, Jung
name: Chen, Chuan-Ren
name: Chiang, Cheng-Wei
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Higgs bosons pair production is well known for its sensitivity to probing the sign and size of Higgs boson self coupling, providing a way to determine whether there is an extended Higgs sector. The Georgi-Machacek (GM) model extends the Standard Model (SM) with an $SU(2)_L$ triplet scalar field that has one real and one complex components. The Higgs self coupling now has a wider range than that in the SM, with even the possibility of a sign flip. The new heavy singlet Higgs boson $H^{0}_{1}$ can contribute to s-channel production of the $hh$ pairs. In this work, we study non-resonant/resonant Higgs boson pair productions $p p \rightarrow hh$ and $p p \rightarrow H^{0}_{1} \rightarrow hh$, focusing exclusively on the contribution of $H^0_1$. We show the sensitivity for Higgs boson pair production searches at the 13-TeV LHC with the luminosities of $3.2,\ 30$ and $100$~fb$^{-1}$.
description: 22 pages, 17 figures
Critical groups for Hopf algebra modules
Creators: name: Grinberg, Darij
name: Huang, Jia
name: Reiner, Victor
Publisher: name: arXiv
Year: 2017
Subjects: subject: Combinatorics (math.CO)
subject: Rings and Algebras (math.RA)
subject: Representation Theory (math.RT)
subject: FOS: Mathematics
subject: 05E10, 16T05, 16T30, 15B48, 20C20

description: This paper considers an invariant of modules over a finite-dimensional Hopf algebra, called the critical group. This generalizes the critical groups of complex finite group representations studied by Benkart, Klivans, Reiner and Gaetz. A formula is given for the cardinality of the critical group generally, and the critical group for the regular representation is described completely. A key role in the formulas is played by the greatest common divisor of the dimensions of the indecomposable projective representations.
description: 24 pages. Comments are welcome! The ancillary file is a longer version with some more details and alternative proofs (compiled from the same source). The version on http://www.cip.ifi.lmu.de/~grinberg/algebra/ will probably get quicker updates. v3: Minor corrections
On a three-dimensional Riccati differential equation and its symmetries
Creators: name: Papillon, Charles
name: Tremblay, Sébastien
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: A three-dimensional Riccati differential equation of complex quaternion-valued functions is studied. Many properties similar to those of the ordinary differential Riccati equation such that linearization and Picard theorem are obtained. Lie point symmetries of the quaternionic Riccati equation are calculated as well as the form of the associated three-dimensional potential of the Schrödinger equation. Using symmetry reductions and relations between the three-dimensional Riccati and the Schrödinger equation, examples are given to obtain solutions of both equations.
description: 21 pages, 0 figure
Influence of the hadronic phase on observables in ultrarelativistic heavy ion collisions
Creators: name: Steinheimer, J.
name: Aichelin, J.
name: Bleicher, M.
name: Stöcker, H.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Nuclear Theory (nucl-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The hadronic phase in ultrarelativistic nuclear collisions has a large influence on final state observables like multiplicity, flow and $p_t$ spectra, as studied in the UrQMD approach. In this model one assumes that a non-equilibrium decoupling phase follows a fluid dynamical description of the high density phase. Hadrons are produced assuming local thermal equilibrium and dynamically decouple during the hadronic rescattering until the particles are registered in the detectors. This rescattering of hadrons modifies every hadronic bulk observable. The apparent multiplicity of resonances is suppressed as compared to a chemical equilibrium freeze-out model, because the decay products rescatter. Therefore the resonances, which decay in the early hadronic phase, cannot be identified anymore by the invariant mass method. Stable and unstable particles change their momentum distribution by more than 30$\%$ through rescattering and their multiplicity is modified by resonance production and annihilation on a similar magnitude. These findings show that it is all but trivial to conclude from the final state observables on the properties of the system at an earlier time where it may have been in local equilibrium.
description: 10 pages 17 figures, version accepted by PRC
Fault-Tolerant Quantum Computing in the Pauli or Clifford Frame with Slow Error Diagnostics
Creators: name: Chamberland, Christopher
name: Iyer, Pavithran
name: Poulin, David
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We consider the problem of fault-tolerant quantum computation in the presence of slow error diagnostics, either caused by measurement latencies or slow decoding algorithms. Our scheme offers a few improvements over previously existing solutions, for instance it does not require active error correction and results in a reduced error-correction overhead when error diagnostics is much slower than the gate time. In addition, we adapt our protocol to cases where the underlying error correction strategy chooses the optimal correction amongst all Clifford gates instead of the usual Pauli gates. The resulting Clifford frame protocol is of independent interest as it can increase error thresholds and could find applications in other areas of quantum computation.
description: 11 pages, 6 figures. Comments welcome! v2: Included version accepted to the Quantum journal
Kalman filter tracking on parallel architectures
Creators: name: Cerati, Giuseppe
name: Elmer, Peter
name: Krutelyov, Slava
name: Lantz, Steven
name: Lefebvre, Matthieu
name: McDermott, Kevin
name: Riley, Daniel
name: Tadel, Matevž
name: Wittich, Peter
name: Würthwein, Frank
name: Yagil, Avi
Publisher: name: arXiv
Year: 2017
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: High Energy Physics - Experiment (hep-ex)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: FOS: Physical sciences

description: Limits on power dissipation have pushed CPUs to grow in parallel processing capabilities rather than clock rate, leading to the rise of "manycore" or GPU-like processors. In order to achieve the best performance, applications must be able to take full advantage of vector units across multiple cores, or some analogous arrangement on an accelerator card. Such parallel performance is becoming a critical requirement for methods to reconstruct the tracks of charged particles at the Large Hadron Collider and, in the future, at the High Luminosity LHC. This is because the steady increase in luminosity is causing an exponential growth in the overall event reconstruction time, and tracking is by far the most demanding task for both online and offline processing. Many past and present collider experiments adopted Kalman filter-based algorithms for tracking because of their robustness and their excellent physics performance, especially for solid state detectors where material interactions play a significant role. We report on the progress of our studies towards a Kalman filter track reconstruction algorithm with optimal performance on manycore architectures. The combinatorial structure of these algorithms is not immediately compatible with an efficient SIMD (or SIMT) implementation; the challenge for us is to recast the existing software so it can readily generate hundreds of shared-memory threads that exploit the underlying instruction set of modern processors. We show how the data and associated tasks can be organized in a way that is conducive to both multithreading and vectorization. We demonstrate very good performance on Intel Xeon and Xeon Phi architectures, as well as promising first results on Nvidia GPUs.
description: Proceedings of the 22nd International Conference on Computing in High Energy and Nuclear Physics, CHEP 2016; 8 pages, 9 figures
Verzeichnis der mineralogischen, geologischen, urgeschichtlichen und hydrologischen Literatur von Württemberg, Hohenzollern und den angrenzenden Gebieten
Creators: name: Unkn
Publisher: name: unkn
Year: 2021

description: Beilagen zu den Jahresheften des Vereins für Vaterländische Naturkunde in Württemberg
description: 3, 1904 [JVVNW 60, 1904]
Nachträge zur Literatur von 1902 und die Literatur von 1903
Creators: name: Schütze, Ewald
Publisher: name: unkn
Year: 2021

description: Beilagen zu den Jahresheften des Vereins für Vaterländische Naturkunde in Württemberg
description: 3, 1904 [JVVNW 60, 1904]
Skew Howe duality and random rectangular Young tableaux
Creators: name: Panova, Greta
name: Śniady, Piotr
Publisher: name: arXiv
Year: 2017
Subjects: subject: Combinatorics (math.CO)
subject: Representation Theory (math.RT)
subject: FOS: Mathematics
subject: 22E46 (Primary)20C30, 60C05 (Secondary)

description: We consider the decomposition into irreducible components of the external power $Λ^p(\mathbb{C}^m\otimes \mathbb{C}^n)$ regarded as a $\operatorname{GL}_m\times\operatorname{GL}_n$-module. Skew Howe duality implies that the Young diagrams from each pair $(λ,μ)$ which contributes to this decomposition turn out to be conjugate to each other, i.e.~$μ=λ'$. We show that the Young diagram $λ$ which corresponds to a randomly selected irreducible component $(λ,λ')$ has the same distribution as the Young diagram which consists of the boxes with entries $\leq p$ of a random Young tableau of rectangular shape with $m$ rows and $n$ columns. This observation allows treatment of the asymptotic version of this decomposition in the limit as $m,n,p\to\infty$ tend to infinity.
description: 17 pages. Version 2: change of title, section on bijective proofs improved
Entanglement and fluctuations in the XXZ model with power-law interactions
Creators: name: Frérot, Irénée
name: Naldesi, Piero
name: Roscilde, Tommaso
Publisher: name: arXiv
Year: 2017
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Gases (cond-mat.quant-gas)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We investigate the ground-state properties of the XXZ model with $1/r^α$ interactions, describing spins interacting with long-range (LR) transverse (XX) ferromagnetic interactions and longitudinal (Z) antiferromagnetic interactions, or hardcore bosons with LR repulsion and hopping. The LR nature of the couplings allows us to quantitatively study the spectral, correlation and entanglement properties of the system by making use of linear spin-wave theory, supplemented with density-matrix renormalization group in one-dimensional systems. Our most important prediction is the existence of three distinct coupling regimes, depending on the decay exponent $α$ and number of dimensions $d$: 1) a short-range regime for $α> d + σ_c$ (where $σ_c = 1$ in the gapped Néel antiferromagnetic phase exhibited by the XXZ model, and $σ_c = 2$ in the gapless XY ferromagnetic phase), sharing the same properties as those of finite-range interactions ($α=\infty$); 2) a long-range regime $α< d$, sharing the same properties as those of the infinite-range interactions ($α=0$) in the thermodynamic limit; and 3) a most intriguing medium-range regime for $d < α< d+σ_c$, continuously interpolating between the finite-range and the infinite-range behavior. The latter regime is characterized by elementary excitations with a long-wavelength dispersion relation $ω\approx Δ_g + ck^z$ in the gapped phase, and $ω\sim k^z$ in the gapless phase, exhibiting a continuously varying dynamical exponent $z = (α- d) / σ_c$. In the gapless phase of the model the $z$ exponent is found to control the scaling of fluctuations, the decay of correlations, and a universal sub-dominant term in the entanglement entropy, leading to a very rich palette of behaviors for ground-state quantum correlations beyond what is known for finite-range interactions.
description: 21 pages, 13 figures
Finite-size Gap, Magnetization, and Entanglement of Deformed Fredkin Spin Chain
Creators: name: Udagawa, Takuma
name: Katsura, Hosho
Publisher: name: arXiv
Year: 2017
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Mathematical Physics (math-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We investigate ground- and excited-state properties of the deformed Fredkin spin chain proposed by Salberger, Zhang, Klich, Korepin, and the authors. This model is a one-parameter deformation of the Fredkin spin chain, whose Hamiltonian is $3$-local and translationally invariant in the bulk. The model is frustration-free and its unique ground state can be expressed as a weighted superposition of colored Dyck paths. We focus on the case where the deformation parameter $t>1$. By using a variational method, we prove that the finite-size gap decays at least exponentially with increasing the system size. We prove that the magnetization in the ground state is along the $z$-direction, namely $\langle s^x \rangle =\langle s^y \rangle=0$, and show that the $z$-component $\langle s^z \rangle$ exhibits a domain-wall structure. We then study the entanglement properties of the chain. In particular, we derive upper and lower bounds for the von Neumann and Rényi entropies, and entanglement spectrum for any bipartition of the chain.
description: 16 pages, 5 figures. v2: Sec. 5.3 has been modified, references added v3: Sec. 4.2 has been modified
The landscape of $W^{\pm}$ and $Z$ bosons produced in $pp$ collisions up to LHC energies
Creators: name: Basso, Eduardo
name: Bourrely, Claude
name: Pasechnik, Roman
name: Soffer, Jacques
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We consider a selection of recent experimental results on electroweak $W^{\pm},\,Z$ gauge boson production in $pp$ collisions at BNL RHIC and CERN LHC energies in comparison to prediction of perturbative QCD calculations based on different sets of NLO parton distribution functions including the statistical PDF model known from fits to the DIS data. We show that the current statistical PDF parameterisation (fitted to the DIS data only) underestimates the LHC data on $W^{\pm},\,Z$ gauge boson production cross sections at the NLO by about 20\%. This suggests that there is a need to refit the parameters of the statistical PDF including the latest LHC data.
description: 16 pages, 8 figures; discussion extended, typos fixed; published version
Corotating Magnetic Reconnection Site in Saturn's Magnetosphere
Creators: name: Yao, Zhonghua
name: Coates, A. J.
name: Ray, L. C.
name: Rae, I. J.
name: Grodent, D.
name: Jones, G. H.
name: Dougherty, M. K.
name: Owen, C. J.
name: Guo, R. L.
name: Dunn, W.
name: Radioti, A.
name: Pu, Z. Y.
name: Lewis, G. R.
name: Waite, J. H.
name: Gerard, J. -C.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: Using measurements from the Cassini spacecraft in Saturn's magnetosphere, we propose a 3D physical picture of a corotating reconnection site, which can only be driven by an internally generated source. Our results demonstrate that the corotating magnetic reconnection can drive an expansion of the current sheet in Saturn's magnetosphere and, consequently, can produce Fermi acceleration of electrons. This reconnection site lasted for longer than one of Saturn's rotation period. The long-lasting and corotating natures of the magnetic reconnection site at Saturn suggest fundamentally different roles of magnetic reconnection in driving magnetospheric dynamics (e.g., the auroral precipitation) from the Earth. Our corotating reconnection picture could also potentially shed light on the fast rotating magnetized plasma environments in the solar system and beyond.
description: 7 pages, 5 figures
The sign of the dipole-dipole potential by axion exchange
Creators: name: Daido, Ryuji
name: Takahashi, Fuminobu
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Experiment (hep-ex)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We calculate a dipole-dipole potential between fermions mediated by a light pseudoscalar, axion, paying a particular attention to the overall sign. While the sign of the potential is physical and important for experiments to discover or constrain the axion coupling to fermions, there is often a sign error in the literature. The purpose of this short note is to clarify the sign issue of the axion-mediated dipole-dipole potential. As a by-product, we find a sign change of the dipole-dipole potenital due to the different spin of the mediating particle.
description: 8 pages, 1 figure. v2: a reference added, matches version published in PLB
Constant Symplectic 2-groupoids
Creators: name: Mehta, Rajan Amit
name: Tang, Xiang
Publisher: name: arXiv
Year: 2017
Subjects: subject: Symplectic Geometry (math.SG)
subject: Algebraic Geometry (math.AG)
subject: Differential Geometry (math.DG)
subject: FOS: Mathematics

description: We propose a definition of symplectic 2-groupoid which includes integrations of Courant algebroids that have been recently constructed. We study in detail the simple but illustrative case of constant symplectic 2-groupoids. We show that the constant symplectic 2-groupoids are, up to equivalence, in one-to-one correspondence with a simple class of Courant algebroids that we call constant Courant algebroids. Furthermore, we find a correspondence between certain Dirac structures and Lagrangian sub-2-groupoids.
description: 17 pages