cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Irreducible compositions of degree two polynomials over finite fields have regular structure
Creators: name: Ferraguti, Andrea
name: Micheli, Giacomo
name: Schnyder, Reto
Publisher: name: arXiv
Year: 2017
Subjects: subject: Number Theory (math.NT)
subject: Formal Languages and Automata Theory (cs.FL)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences
subject: 11T06, 68Q45

description: Let $q$ be an odd prime power and $D$ be the set of monic irreducible polynomials in $\mathbb F_q[x]$ which can be written as a composition of monic degree two polynomials. In this paper we prove that $D$ has a natural regular structure by showing that there exists a finite automaton having $D$ as accepted language. Our method is constructive.
description: To appear in The Quarterly Journal of Mathematics
Compressible-incompressible two-phase flows with phase transition: model problem
Creators: name: Watanabe, Keiichi
Publisher: name: arXiv
Year: 2017
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: 35Q30 (Primary), 76T10 (Secondary)

description: We study the compressible and incompressible two-phase flows separated by a sharp interface with a phase transition and a surface tension. In particular, we consider the problem in $\mathbb{R}^N$, and the Navier-Stokes-Korteweg equations is used in the upper domain and the Navier-Stokes equations is used in the lower domain. We prove the existence of $\mathcal{R}$-bounded solution operator families for a resolvent problem arising from its model problem. According to Shibata \cite{GS2014}, the regularity of $ρ_+$ is $W^1_q$ in space, but to solve the kinetic equation: $\mathbf{u}_Γ\cdot\mathbf{n}_t = [[ρ\mathbf{u}]]\cdot\mathbf{n}_t /[[ρ]]$ on $Γ_t$ we need $W^{2-1/q}_q$ regularity of $ρ_+$ on $Γ_t$, which means the regularity loss. Since the regularity of $ρ_+$ dominated by the Navier-Stokes-Korteweg equations is $W^3_q$ in space, we eliminate the problem by using the Navier-Stokes-Korteweg equations instead of the compressible Navier-Stokes equations.
description: Typos corrected
Natural Covariant Planck Scale Cutoffs and the Cosmic Microwave Background Spectrum
Creators: name: Chatwin-Davies, Aidan
name: Kempf, Achim
name: Martin, Robert T. W.
Publisher: name: arXiv
Year: 2016
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We calculate the impact of quantum gravity-motivated ultraviolet cutoffs on inflationary predictions for the cosmic microwave background spectrum. We model the ultraviolet cutoffs fully covariantly to avoid possible artifacts of covariance breaking. Imposing these covariant cutoffs results in the production of small, characteristically $k-$dependent oscillations in the spectrum. The size of the effect scales linearly with the ratio of the Planck to Hubble lengths during inflation. Consequently, the relative size of the effect could be as large as one part in $10^5$; i.e., eventual observability may not be ruled out.
description: 5 pages, 3 figures - v2: minor corrections, added references -v3: harmonize with published version
On the Flow of $\Box R$ Weyl-Anomaly
Creators: name: Prochazka, Vladimir
name: Zwicky, Roman
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: An important aspect of Weyl anomalies is that they encode information on the irreversibility of the renormalisation group flow. We consider, $Δ\bar b = \bar{b}^{\textrm{UV}} - \bar{b}^{\textrm{IR}}$, the difference of the ultraviolet and infrared value of the $\Box R$-term of the Weyl anomaly. The quantity is related to the fourth moment of the trace of the energy momentum tensor correlator for theories which are conformal at both ends. Subtleties arise for non-conformal fixed points as might be the case for infrared fixed points with broken chiral symmetry. Provided that the moment converges, $Δ\bar{b}$ is then automatically positive by unitarity. Written as an integral over the renormalisation scale, flow-independence follows since its integrand is a total derivative. Furthermore, using a momentum subtraction scheme (MOM) the 4D Zamolodchikov- metric is shown to be strictly positive beyond perturbation theory and equivalent to the metric of a conformal manifold at both ends of the flow. In this scheme $\bar{b}(μ)$ can be extended outside the fixed point to a monotonically decreasing function. The ultraviolet finiteness of the fourth moment enables us to define a scheme for the $δ{\cal L} \sim b_0 R^2$-term, for which the $R^2$-anomaly vanishes along the flow. In the MOM- and the $R^2$-scheme, $\bar{b}(μ)$ is shown to satisfy a gradient flow type equation. We verify our findings in free field theories, higher derivative theories and extend $Δ\bar{b}$ and the Euler flow $Δβ_a$ for a Caswell-Banks-Zaks fixed point for QCD-like theories to next-to-next-to leading order using a recent $\langle G^2G^2 \rangle$-correlator computation.
description: 28 pp + refs + 1 fig, v2 quasi identical to PRD-version
MPEC 2023-R155 : 2023 RO5
Creators: name: Minor Planet Center Staff
Publisher: name: The Minor Planet Center
Year: 2023
Subjects: subject: Small Solar System bodies
valueUri: http://astrothesaurus.org/uat/1469
subject: 2023 RO5

description: The Minor Planet Electronic Circulars contain information on unusual minor planets, routine data on comets and natural satellites, and occasional editorial announcements.  They are published on behalf of Division F of the International Astronomical Union by the Minor Planet Center, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Pseudo-Goldstone magnons in the frustrated S=3/2 Heisenberg helimagnet ZnCr2Se4 with a pyrochlore magnetic sublattice
Creators: name: Tymoshenko, Y. V.
name: Onykiienko, Y. A.
name: Mueller, T.
name: Thomale, R.
name: Rachel, S.
name: Cameron, A. S.
name: Portnichenko, P. Y.
name: Efremov, D. V.
name: Tsurkan, V.
name: Abernathy, D. L.
name: Ollivier, J.
name: Schneidewind, A.
name: Piovano, A.
name: Felea, V.
name: Loidl, A.
name: Inosov, D. S.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Low-energy spin excitations in any long-range ordered magnetic system in the absence of magnetocrystalline anisotropy are gapless Goldstone modes emanating from the ordering wave vectors. In helimagnets, these modes hybridize into the so-called helimagnon excitations. Here we employ neutron spectroscopy supported by theoretical calculations to investigate the magnetic excitation spectrum of the isotropic Heisenberg helimagnet ZnCr2Se4 with a cubic spinel structure, in which spin-3/2 magnetic Cr3+ ions are arranged in a geometrically frustrated pyrochlore sublattice. Apart from the conventional Goldstone mode emanating from the (0 0 q) ordering vector, low-energy magnetic excitations in the single-domain proper-screw spiral phase show soft helimagnon modes with a small energy gap of ~0.17 meV, emerging from two orthogonal wave vectors (q 0 0) and (0 q 0) where no magnetic Bragg peaks are present. We term them pseudo-Goldstone magnons, as they appear gapless within linear spin-wave theory and only acquire a finite gap due to higher-order quantum-fluctuation corrections. Our results are likely universal for a broad class of symmetric helimagnets, opening up a new way of studying weak magnon-magnon interactions with accessible spectroscopic methods.
description: V3: Final version to be published in Phys. Rev. X
Shuffle group laws. Applications in free probability
Creators: name: Ebrahimi-Fard, Kurusch
name: Patras, Frederic
Publisher: name: arXiv
Year: 2017
Subjects: subject: Rings and Algebras (math.RA)
subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 16T05, 16T10, 16T30, 46L53, 46L54

description: Commutative shuffle products are known to be intimately related to universal formulas for products, exponentials and logarithms in group theory as well as in the theory of free Lie algebras, such as, for instance, the Baker-Campbell-Hausdorff formula or the analytic expression of a Lie group law in exponential coordinates in the neighbourhood of the identity. Non-commutative shuffle products happen to have similar properties with respect to pre-Lie algebras. However, the situation is more complex since in the non-commutative framework three exponential-type maps and corresponding logarithms are naturally defined. This results in several new formal group laws together with new operations - for example a new notion of adjoint action particularly well fitted to the new theory. These developments are largely motivated by various constructions in non-commutative probability theory. The second part of the article is devoted to exploring and deepening this perspective. We illustrate our approach by revisiting universal products from a group-theoretical viewpoint, including additive convolution in monotone, free and boolean probability, as well as the Bercovici-Pata bijection and subordination products.
description: revised manuscript
Excess entropy production in quantum system: Quantum master equation approach
Creators: name: Nakajima, Satoshi
name: Tokura, Yasuhiro
Publisher: name: arXiv
Year: 2016
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: For open systems described by the quantum master equation (QME), we investigate the excess entropy production under quasistatic operations between nonequilibrium steady states. The average entropy production is composed of the time integral of the instantaneous steady entropy production rate and the excess entropy production. We propose to define average entropy production rate using the average energy and particle currents, which are calculated by using the full counting statistics with QME. The excess entropy production is given by a line integral in the control parameter space and its integrand is called the Berry-Sinitsyn-Nemenman (BSN) vector. In the weakly nonequilibrium regime, we show that BSN vector is described by $\ln \breveρ_0$ and $ρ_0$ where $ρ_0$ is the instantaneous steady state of the QME and $\breveρ_0$ is that of the QME which is given by reversing the sign of the Lamb shift term. If the system Hamiltonian is non-degenerate or the Lamb shift term is negligible, the excess entropy production approximately reduces to the difference between the von Neumann entropies of the system. Additionally, we point out that the expression of the entropy production obtained in the classical Markov jump process is different from our result and show that these are approximately equivalent only in the weakly nonequilibrium regime.
description: 27pages, No figure, J. Stat. Phys. (2017)
Mass Conservative and Energy Stable Finite Difference Methods for the Quasi-incompressible Navier-Stokes-Cahn-Hilliard system: Primitive Variable and Projection-Type Schemes
Creators: name: Guo, Zhenlin
name: Lin, Ping
name: Wise, Steven
name: Lowengrub, John
Publisher: name: arXiv
Year: 2017
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics

description: In this paper we describe two fully mass conservative, energy stable, finite difference methods on a staggered grid for the quasi-incompressible Navier-Stokes-Cahn-Hilliard (q-NSCH) system governing a binary incompressible fluid flow with variable density and viscosity. Both methods, namely the primitive method (finite difference method in the primitive variable formulation) and the projection method (finite difference method in a projection-type formulation), are so designed that the mass of the binary fluid is preserved, and the energy of the system equations is always non-increasing in time at the fully discrete level. We also present an efficient, practical nonlinear multigrid method - comprised of a standard FAS method for the Cahn-Hilliard equation, and a method based on the Vanka-type smoothing strategy for the Navier-Stokes equation - for solving these equations. We test the scheme in the context of Capillary Waves, rising droplets and Rayleigh-Taylor instability. Quantitative comparisons are made with existing analytical solutions or previous numerical results that validate the accuracy of our numerical schemes. Moreover, in all cases, mass of the single component and the binary fluid was conserved up to 10 to -8 and energy decreases in time.
The transition of a gravitationally radiating, dissipative fluid, to equilibrium
Creators: name: Herrera, L.
name: Di Prisco, A.
name: Ospino, J.
Publisher: name: arXiv
Year: 2017
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We describe the transition of a graviationally radiating, axially and reflection symmetric dissipative fluid, to a non--radiating state. It is shown that very shortly after the end of the radiating regime, at a time scale of the order the thermal relaxation time, the thermal adjustment time and the hydrostatic time (whichever is larger), the system reaches the equilibrium state. This result is at variance with all the studies carried out in the past, on gravitational radiation outside the source, which strongly suggest that after a radiating period, the conditions for a return to a static case, look rather forbidding. As we shall see, the reason for such a discrepancy resides in the fact that some elementary, but essential, physical properties of the source, have been overlooked in these latter studies.
description: 7 pages, latex. arXiv admin note: substantial text overlap with arXiv:1609.02841. Some typos corrected. Published in Canadian Journal of Physics
Machine Learning based tool for CMS RPC currents quality monitoring
Creators: name: Shumka, E.
name: Samalan, A.
name: Tytgat, M.
name: El Sawy, M.
name: Alves, G. A.
name: Marujo, F.
name: Coelho, E. A.
name: Da Costa, E. M.
name: Nogima, H.
name: Santoro, A.
name: De Souza, S. Fonseca
name: De Jesus Damiao, D.
name: Thiel, M.
name: Amarilo, K. Mota
name: Filho, M. Barroso Ferreira
name: Aleksandrov, A.
name: Hadjiiska, R.
name: Iaydjiev, P.
name: Rodozov, M.
name: Shopova, M.
name: Soultanov, G.
name: Dimitrov, A.
name: Litov, L.
name: Pavlov, B.
name: Petkov, P.
name: Petrov, A.
name: Qian, S. J.
name: Kou, H.
name: Liu, Z.-A.
name: Zhao, J.
name: Song, J.
name: Hou, Q.
name: Diao, W.
name: Cao, P.
name: Avila, C.
name: Barbosa, D.
name: Cabrera, A.
name: Florez, A.
name: Fraga, J.
name: Reyes, J.
name: Assran, Y.
name: Mahmoud, M. A.
name: Mohammed, Y.
name: Crotty, I.
name: Laktineh, I.
name: Grenier, G.
name: Gouzevitch, M.
name: Mirabito, L.
name: Shchablo, K.
name: Bagaturia, I.
name: Lomidze, I.
name: Tsamalaidze, Z.
name: Amoozegar, V.
name: Boghrati, B.
name: Ebraimi, M.
name: Najafabadi, M. Mohammadi
name: Zareian, E.
name: Abbrescia, M.
name: Iaselli, G.
name: Pugliese, G.
name: Loddo, F.
name: De Filippis, N.
name: Aly, R.
name: Ramos, D.
name: Elmetenawee, W.
name: Leszki, S.
name: Margjeka, I.
name: Paesani, D.
name: Benussi, L.
name: Bianco, S.
name: Piccolo, D.
name: Meola, S.
name: Buontempo, S.
name: Carnevali, F.
name: Lista, L.
name: Paolucci, P.
name: Fienga, F.
name: Braghieri, A.
name: Salvini, P.
name: Montagna, P.
name: Riccardi, C.
name: Vitulo, P.
name: Asilar, E.
name: Choi, J.
name: Kim, T. J.
name: Choi, S. Y.
name: Hong, B.
name: Lee, K. S.
name: Oh, H. Y.
name: Goh, J.
name: Yu, I.
name: Estrada, C. Uribe
name: Pedraza, I.
name: Castilla-Valdez, H.
name: Sanchez-Hernandez, A.
name: Fernandez, R. L.
name: Ramirez-Garcia, M.
name: Vazquez, E.
name: Shah, M. A.
name: Zaganidis, N.
name: Radi, A.
name: Hoorani, H.
name: Muhammad, S.
name: Ahmad, A.
name: Asghar, I.
name: Khan, W. A.
name: Eysermans, J.
name: Torres Da Silva De Araujo, Felipe
name: CMS Muon Group
Publisher: name: RWTH Aachen University
Year: 2023
Subjects: subject: 530

description: 6 Seiten (2023).
A Quantum Window Onto Early Inflation
Creators: name: Hardwick, Robert J.
name: Vennin, Vincent
name: Wands, David
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Inflation in the early Universe is one of the most promising probes of gravity in the high-energy regime. However, observable scales give access to a limited window in the inflationary dynamics. In this essay, we argue that quantum corrections to the classical dynamics of cosmological fields allow us to probe much earlier epochs of the inflationary phase and extend this window by many orders of magnitude. We point out that both the statistics of cosmological fluctuations at observable scales, and the field displacements acquired by spectator fields that play an important role in many post-inflationary processes, are sensitive to a much longer phase of the inflationary epoch.
description: 5 pages, 2 figures. Honourable Mention from the Gravity Research Foundation 2017 Awards for Essays on Gravitation. Version to appear in October 2017 Special Issue of the International Journal of Modern Physics D. Updated to match the published version
MPEC 2023-R156 : 2023 RP5
Creators: name: Minor Planet Center Staff
Publisher: name: The Minor Planet Center
Year: 2023
Subjects: subject: Small Solar System bodies
valueUri: http://astrothesaurus.org/uat/1469
subject: 2023 RP5

description: The Minor Planet Electronic Circulars contain information on unusual minor planets, routine data on comets and natural satellites, and occasional editorial announcements.  They are published on behalf of Division F of the International Astronomical Union by the Minor Planet Center, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
pH dependence of charge multipole moments in proteins
Creators: name: Bozic, Anze Losdorfer
name: Podgornik, Rudolf
Publisher: name: arXiv
Year: 2017
Subjects: subject: Biological Physics (physics.bio-ph)
subject: Soft Condensed Matter (cond-mat.soft)
subject: Biomolecules (q-bio.BM)
subject: FOS: Physical sciences
subject: FOS: Biological sciences

description: Electrostatic interactions play a fundamental role in the structure and function of proteins. Due to ionizable amino acid residues present on the solvent-exposed surfaces of proteins, the protein charge is not constant but varies with the changes in the environment -- most notably, the pH of the surrounding solution. We study the effects of pH on the charge of four globular proteins by expanding their surface charge distributions in terms of multipoles. The detailed representation of the charges on the proteins is in this way replaced by the magnitudes and orientations of the multipole moments of varying order. Focusing on the three lowest-order multipoles -- the total charge, dipole, and quadrupole moment -- we show that the value of pH influences not only their magnitudes, but more notably and importantly also the spatial orientation of their principal axes. Our findings imply important consequences for the study of protein-protein interactions and the assembly of both proteinaceous shells and patchy colloids with dissociable charge groups.
description: 15 pages, 6 figures; 12 pages and 12 figures of Supporting Material; accepted for publication in Biophysical Journal
Tracing the boundaries: women, nation & modernity in Turkey
Creators: name: Yilmaz, Aybige
Publisher: name: University of Westminster
Year: 2007

description: This research project examines the dominant discourses of national identity and delineates the processes of othering in contemporary Turkey. It does this by following the various debates that have surfaced around women in Turkey. The data that informs this process consists of news coverage of selected case studies about women in mainstream Turkish newspapers. In doing so, the research also examines the role of women in the articulation of national boundaries. In doing this, the research builds on the arguments developed by studies of nationalism and postcolonial theory that focus on the close relationship between the discourses of nationalism, modernity and gender. The analysis of the case studies gives a clear, if not all comprehensive view, of the heated debates going on in Turkey, about what Turkishness entails, and where its identity can be located. While an unambiguous location does not emerge from the analysed data, the different proposals on the meaning of Turkishness which surface through the news stories point towards the opportunities, as well as the threats presented in the articulation of national boundaries. The research reveals that national imagination in Turkey today is still highly informed by the gender, ethnic and modernization discourses that have been anchored in the early years of the Republic. According to this, the symbolic role of women in representing the nation continues to form an obstacle to perceiving them as independent subjects. In discourses of national identity, whereas the ethnic understanding of Turkishness is largely clear and unquestioned, discourses about Turkey's modernity are more ambiguous and point to the hybrid character of the Turkish modernization project. The data also indicates an ambivalent relationship with Europe, which appears both as the desired locus of modernity and a source of threat - thus identifying with it and othering it at the same time. The analysis attempts to trace and interpret those ambivalences and point to where the possibilities for a more inclusionary understanding of national identity can emerge.
Efficient acquisition rules for model-based approximate Bayesian computation
Creators: name: Järvenpää, Marko
name: Gutmann, Michael U.
name: Pleska, Arijus
name: Vehtari, Aki
name: Marttinen, Pekka
Publisher: name: arXiv
Year: 2017
Subjects: subject: Machine Learning (stat.ML)
subject: Computation (stat.CO)
subject: Methodology (stat.ME)
subject: FOS: Computer and information sciences

description: Approximate Bayesian computation (ABC) is a method for Bayesian inference when the likelihood is unavailable but simulating from the model is possible. However, many ABC algorithms require a large number of simulations, which can be costly. To reduce the computational cost, Bayesian optimisation (BO) and surrogate models such as Gaussian processes have been proposed. Bayesian optimisation enables one to intelligently decide where to evaluate the model next but common BO strategies are not designed for the goal of estimating the posterior distribution. Our paper addresses this gap in the literature. We propose to compute the uncertainty in the ABC posterior density, which is due to a lack of simulations to estimate this quantity accurately, and define a loss function that measures this uncertainty. We then propose to select the next evaluation location to minimise the expected loss. Experiments show that the proposed method often produces the most accurate approximations as compared to common BO strategies.
description: 30 pages, 10 figures
The Landau-Lifshitz equation, the NLS, and the magnetic rogue wave as a by-product of two colliding regular "positons"
Creators: name: Yurov, A. V.
name: Yurov, V. A.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: In this article we present a new method for construction of exact solutions of the Landau-Lifshitz-Gilbert equation (LLG) for ferromagnetic nanowires. The method is based on the established relationship between the LLG and the nonlinear Schrödinger equation (NLS), and is aimed at resolving an old problem: how to produce multiple-rogue wave solutions of NLS using just the Darboux-type transformations. The solutions of this type - known as P-breathers - have been proven to exist by Dubard and Matveev, but their technique heavily relied on using the solutions of yet another nonlinear equation, Kadomtsev-Petviashvili I equation (KP-I), and its relationship with NLS. We have shown that in fact one doesn't have to use KP-I but can instead reach the same results just with NLS solutions, but only if they are dressed via the binary Darboux transformation. In particular, our approach allows to construct all the Dubard-Matveev P-breathers. Furthermore, the new method can lead to some completely new, previously unknown solutions. One particular solution that we have constructed describes two positon-like waves, colliding with each other and in the process producing a new, short-lived rogue wave. We called this unusual solution (rogue wave begotten after the impact of two solitons) the "impacton".
description: 25 pages, 9 figures. Added Section 7 ("7. One last remark: But what of generalization?.."), corrected a number of typos, added 2 more references
Entanglement spectrum of the degenerative ground state of Heisenberg ladders in a time-dependent magnetic field
Creators: name: Predin, Sonja
Publisher: name: arXiv
Year: 2017
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We investigate of the relationship between the entanglement and subsystem Hamiltonians in the perturbative regime of strong coupling between subsystems. One of the two conditions that guarantees the proportionality between these Hamiltonians obtained by using the nondegenerate perturbation theory within the first order is that the unperturbed ground state has a trivial entanglement Hamiltonian. Furthermore, we study the entanglement Hamiltonian of the Heisenberg ladders in a time-dependent magnetic field using the degenerate perturbation theory, where couplings between legs are considered as a perturbation. In this case, when the ground state is two-fold degenerate, and the entanglement Hamiltonian is proportional to the Hamiltonian of a chain within first-order perturbation theory, even then also the unperturbed ground state has a nontrivial entanglement spectrum.
description: 1 figure, Refs. added, minor changes
Andreev bound states probed in three-terminal quantum dots
Creators: name: Gramich, J.
name: Baumgartner, A.
name: Schönenberger, C.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We demonstrate several new electron transport phenomena mediated by Andreev bound states (ABSs) that form on three-terminal carbon nanotube (CNT) QDs, with one superconducting (S) contact in the center and two adjacent normal metal (N) contacts. Three-terminal spectroscopy allows us to identify the coupling to the N contacts as the origin of the Andreev resonance (AR) linewidths and to determine the critical coupling strengths to S, for which a ground state transition S-QD systems can occur. We ascribe replicas of the lowest-energy ABS resonance to transitions between the ABS and odd-parity excited QD states, a process called excited state ABS resonances. In the conductance between the two N contacts we find a characteristic pattern of positive and negative differential subgap conductance, which we explain by considering two nonlocal processes, the creation of Cooper pairs in S by electrons from both N terminals, and a novel mechanism called resonant ABS tunneling. In the latter, electrons are transferred via the ABS without creating Cooper pairs in S. The three-terminal geometry also allows spectroscopy experiments with different boundary conditions, for example by leaving S floating. Surprisingly, we find that, depending on the boundary conditions, the experiments either show single-particle Coulomb blockade resonances, ABS characteristics, or both in the same measurements, seemingly contradicting the notion of ABSs replacing the single particle states as eigenstates of the QD. We qualitatively explain these results as originating from the finite time scale required for the coherent oscillations between the superposition states after a single electron tunneling event. These experiments demonstrate that three-terminal experiments on a single complex quantum object can also be useful to investigate charge dynamics otherwise not accessible due to the very high frequencies.
description: 15 pages, 16 figures
Linear response of entanglement entropy from holography
Creators: name: Lokhande, Sagar F.
name: Oling, Gerben W. J.
name: Pedraza, Juan F.
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: For time-independent excited states in conformal field theories, the entanglement entropy of small subsystems satisfies a `first law'-like relation, in which the change in entanglement is proportional to the energy within the entangling region. Such a law holds for time-dependent scenarios as long as the state is perturbatively close to the vacuum, but is not expected otherwise. In this paper we use holography to investigate the spread of entanglement entropy for unitary evolutions of special physical interest, the so-called global quenches. We model these using AdS-Vaidya geometries. We find that the first law of entanglement is replaced by a linear response relation, in which the energy density takes the role of the source and is integrated against a time-dependent kernel with compact support. For adiabatic quenches the standard first law is recovered, while for rapid quenches the linear response includes an extra term that encodes the process of thermalization. This extra term has properties that resemble a time-dependent `relative entropy'. We propose that this quantity serves as a useful order parameter to characterize far-from-equilibrium excited states. We illustrate our findings with concrete examples, including generic power-law and periodically driven quenches.
description: 31+3 pages, 8 figures; v2: typos fixed and references added; v3: claims on universality sharpened (section 2.1), version to appear in JHEP
Loss-Sensitive Generative Adversarial Networks on Lipschitz Densities
Creators: name: Qi, Guo-Jun
Publisher: name: arXiv
Year: 2017
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: In this paper, we present the Lipschitz regularization theory and algorithms for a novel Loss-Sensitive Generative Adversarial Network (LS-GAN). Specifically, it trains a loss function to distinguish between real and fake samples by designated margins, while learning a generator alternately to produce realistic samples by minimizing their losses. The LS-GAN further regularizes its loss function with a Lipschitz regularity condition on the density of real data, yielding a regularized model that can better generalize to produce new data from a reasonable number of training examples than the classic GAN. We will further present a Generalized LS-GAN (GLS-GAN) and show it contains a large family of regularized GAN models, including both LS-GAN and Wasserstein GAN, as its special cases. Compared with the other GAN models, we will conduct experiments to show both LS-GAN and GLS-GAN exhibit competitive ability in generating new images in terms of the Minimum Reconstruction Error (MRE) assessed on a separate test set. We further extend the LS-GAN to a conditional form for supervised and semi-supervised learning problems, and demonstrate its outstanding performance on image classification tasks.
description: The source codes for both LS-GAN and GLS-GAN are available at \url{https://github.com/maple-research-lab}. LS-GAN is also supported by Microsoft CNTK at \url{https://www.cntk.ai/pythondocs/CNTK_206C_WGAN_LSGAN.html}. The original codes of LS-GAN and GLS-GAN are also available at https://github.com/guojunq/lsgan/ and https://github.com/guojunq/glsgan/
Local rings with quasi-decomposable maximal ideal
Creators: name: Nasseh, Saeed
name: Takahashi, Ryo
Publisher: name: arXiv
Year: 2017
Subjects: subject: Commutative Algebra (math.AC)
subject: FOS: Mathematics
subject: 13C60, 13D02, 13D09, 13H10

description: Let $(R,\frak m)$ be a commutative noetherian local ring. In this paper, we prove that if $\frak m$ is decomposable, then for any finitely generated $R$-module $M$ of infinite projective dimension $\frak m$ is a direct summand of (a direct sum of) syzygies of $M$. Applying this result to the case where $\frak m$ is quasi-decomposable, we obtain several classfications of subcategories, including a complete classification of the thick subcategories of the singularity category of $R$.
description: 18 pages. Some minor changes throughout the paper; statement of Corollary 6.5 improved; Remark 6.7, Corollary 6.8, and reference [2] are added. Final version to appear in the Mathematical Proceedings of the Cambridge Philosophical Society
Can black hole superradiance be induced by galactic plasmas?
Creators: name: Conlon, Joseph P.
name: Herdeiro, Carlos A. R.
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Highly spinning Kerr black holes with masses $M = 1 - 100\ M_{\odot}$ are subject to an efficient superradiant instability in the presence of bosons with masses $μ\sim 10^{-10} - 10^{-12}\ {\rm eV}$. We observe that this matches the effective plasma-induced photon mass in diffuse galactic or intracluster environments ($ω_{\rm pl} \sim 10^{-10} - 10^{-12}\ {\rm eV}$). This suggests that bare Kerr black holes within galactic or intracluster environments, possibly even including the ones produced in recently observed gravitational wave events, are unstable to formation of a photon cloud that may contain a significant fraction of the mass of the original black hole. At maximal efficiency, the instability timescale for a massive vector is milliseconds, potentially leading to a transient rate of energy extraction from a black hole in principle as large as $\sim 10^{55} \ {\rm erg \, s}^{-1}$. We discuss possible astrophysical effects this could give rise to, including a speculative connection to Fast Radio Bursts.
description: 5 pages; v2. accepted version
The 2.4 $μ$m Galaxy Luminosity Function as Measured Using WISE. II. Sample Selection
Creators: name: Lake, S. E.
name: Wright, E. L.
name: Assef, R. J.
name: Jarrett, T. H.
name: Petty, S.
name: Stanford, S. A.
name: Stern, D.
name: Tsai, C. -W.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The WISE satellite surveyed the entire sky multiple times in four infrared (IR) wavelengths ($3.4,\ 4.6,\ 12,$ and $22\, μ$m, Wright et al. 2010). This all-sky IR photometric survey makes it possible to leverage many of the large publicly available spectroscopic redshift surveys to measure galaxy properties in the IR. While characterizing the cross-matching of WISE data to a single survey is a straightforward process, doing it with six different redshift surveys takes a fair amount of space to characterize adequately, because each survey has unique caveats and characteristics that need addressing. This work describes a data set that results from matching five public redshift surveys with the AllWISE data release, along with a reanalysis of the data described in Lake et al. 2012. The combined data set has an additional flux limit of $80\,μ$Jy ($19.14$ AB mag) in WISE's W1 filter imposed in order to limit it to targets with high completeness and reliable photometry in the AllWISE data set. Consistent analysis of all of the data is only possible if the color bias discussed in Ilbert et al. (2004) is addressed (for example: the techniques explored in the first paper in this series Lake et al. 2017b). The sample defined herein is used in this paper's sequel paper, Lake et al. 2017a), to measure the luminosity function of galaxies at $2.4\, μ$m rest frame wavelength, and the selection process of the sample is optimized for this purpose.
description: 44 pages, 22 figures, 20 tables, associated data on Figshare under DOIs 10.6084/m9.figshare.3860016 and 10.6084/m9.figshare.4003680, accepted by ApJ
Learning Lyapunov (Potential) Functions from Counterexamples and Demonstrations
Creators: name: Ravanbakhsh, Hadi
name: Sankaranarayanan, Sriram
Publisher: name: arXiv
Year: 2017
Subjects: subject: Systems and Control (eess.SY)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: We present a technique for learning control Lyapunov (potential) functions, which are used in turn to synthesize controllers for nonlinear dynamical systems. The learning framework uses a demonstrator that implements a black-box, untrusted strategy presumed to solve the problem of interest, a learner that poses finitely many queries to the demonstrator to infer a candidate function and a verifier that checks whether the current candidate is a valid control Lyapunov function. The overall learning framework is iterative, eliminating a set of candidates on each iteration using the counterexamples discovered by the verifier and the demonstrations over these counterexamples. We prove its convergence using ellipsoidal approximation techniques from convex optimization. We also implement this scheme using nonlinear MPC controllers to serve as demonstrators for a set of state and trajectory stabilization problems for nonlinear dynamical systems. Our approach is able to synthesize relatively simple polynomial control Lyapunov functions, and in that process replace the MPC using a guaranteed and computationally less expensive controller.
Publisher Correction: Large electrostrictive response in lead halide perovskites
Creators: name: Li, Tao
name: Huang, Jinsong
name: Liu, Ye
name: Gruverman, Alexei
name: Deng, Yehao
name: Song, Jingfeng
name: De Angelis, Filippo
name: Chen, Zhaolai
name: Ducharme, Stephen
name: Mosconi, Edoardo
name: Dong, Qingfeng
name: Chen, Bo
Publisher: name: Springer Nature
Year: 2018

description:
In the version of this Article originally published, the y axis of Fig. 1c was incorrectly labelled ‘S (%)’; it should have been ‘–S (%)’. Also, the link for the Supplementary Video was missing from the online version of the Article. These errors have now been corrected.
The 2.4 $μ$m Galaxy Luminosity Function as Measured Using WISE. III. Measurement Results
Creators: name: Lake, S. E.
name: Wright, E. L.
name: Assef, R. J.
name: Jarrett, T. H.
name: Petty, S.
name: Stanford, S. A.
name: Stern, D.
name: Tsai, C. -W.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The WISE satellite surveyed the entire sky multiple times in four infrared wavelengths (3.4, 4.6, 12, and $22\,μ$m; Wright et al. 2010). The unprecedented combination of coverage area and depth gives us the opportunity to measure the luminosity function of galaxies, one of the fundamental quantities in the study of them, at $2.4\ μ$m to an unparalleled level of formal statistical accuracy in the near infrared. The big advantage of measuring luminosity functions at wavelengths in the window $\approx 2$ to $3.5\,μ$m is that it correlates more closely to the total stellar mass in galaxies than others. In this paper we report on the parameters for the $2.4\,μ$m luminosity function of galaxies obtained from applying the spectroluminosity functional based methods defined in Lake et al. (2017b) to the data sets described in Lake et al. (2017a) using the mean and covariance of $2.4\,μ$m normalized SEDs from Lake & Wright (2016). In terms of single Schechter function parameters evaluated at the present epoch, the combined result is: $ϕ_\star = 5.8 \pm [0.3_{\mathrm{stat}},\, 0.3_{\mathrm{sys}}] \times 10^{-3} \operatorname{Mpc}^{-3}$, $L_\star = 6.4 \pm [0.1_{\mathrm{stat}},\, 0.3_{\mathrm{sys}}] \times 10^{10}\, L_{2.4\,μ\mathrm{m}\,\odot}$ ($M_\star = -21.67 \pm [0.02_{\mathrm{stat}},\, 0.05_{\mathrm{sys}}]\operatorname{AB\ mag}$), and $α= -1.050 \pm [0.004_{\mathrm{stat}},\, 0.03_{\mathrm{sys}}]$, corresponding to a galaxy number density of $0.08\operatorname{Mpc}^{-3}$ brighter than $10^6\, L_{2.4\,μ\mathrm{m}\,\odot}$ ($10^{-3} \operatorname{Mpc}^{-3}$ brighter than $L_\star$) and a $2.4\,μ$m luminosity density equivalent to $3.8\times10^{8}\,L_{2.4\,μ\mathrm{m}\,\odot}\operatorname{Mpc}^{-3}$. $\ldots$
description: 25 pages, 7 figures, 10 tables, posterior chains on Figshare under DOI 10.6084/m9.figshare.4109625, accepted by ApJ
The matter-ekpyrotic bounce scenario in Loop Quantum Cosmology
Creators: name: Haro, Jaume
name: Amorós, Jaume
name: Saló, Llibert Aresté
Publisher: name: arXiv
Year: 2017
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We will perform a detailed study of the matter-ekpyrotic bouncing scenario in Loop Quantum Cosmology using the methods of the dynamical systems theory. We will show that when the background is driven by a single scalar field, at very late times, in the contracting phase, all orbits depict a matter dominated Universe, which evolves to an ekpyrotic phase. After the bounce the Universe enters in the expanding phase, where the orbits leave the ekpyrotic regime going to a kination (also named deflationary) regime. Moreover, this scenario supports the production of heavy massive particles conformally coupled with gravity, which reheats the universe at temperatures compatible with the nucleosynthesis bounds and also the production of massless particles non-conformally coupled with gravity leading to very high reheating temperatures but ensuring the nucleosynthesis success. Dealing with cosmological perturbations, these background dynamics produce a nearly scale invariant power spectrum for the modes that leave the Hubble radius, in the contracting phase, when the Universe is quasi-matter dominated, whose spectral index and corresponding running is compatible with the recent experimental data obtained by PLANCK's team.
description: 39 pages, 19 figures. Version accepted for publication in JCAP
Ensemble Kalman methods for high-dimensional hierarchical dynamic space-time models
Creators: name: Katzfuss, Matthias
name: Stroud, Jonathan R.
name: Wikle, Christopher K.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Methodology (stat.ME)
subject: Computation (stat.CO)
subject: FOS: Computer and information sciences

description: We propose a new class of filtering and smoothing methods for inference in high-dimensional, nonlinear, non-Gaussian, spatio-temporal state-space models. The main idea is to combine the ensemble Kalman filter and smoother, developed in the geophysics literature, with state-space algorithms from the statistics literature. Our algorithms address a variety of estimation scenarios, including on-line and off-line state and parameter estimation. We take a Bayesian perspective, for which the goal is to generate samples from the joint posterior distribution of states and parameters. The key benefit of our approach is the use of ensemble Kalman methods for dimension reduction, which allows inference for high-dimensional state vectors. We compare our methods to existing ones, including ensemble Kalman filters, particle filters, and particle MCMC. Using a real data example of cloud motion and data simulated under a number of nonlinear and non-Gaussian scenarios, we show that our approaches outperform these existing methods.
Elucidation of the Mechanism of Elicitation in Penicillium Chrysogenum: Systematic Approach to Study the Effect of Oligosaccharides on Production of Penicillin G
Creators: name: Nair, Rakesh
Publisher: name: University of Westminster
Year: 2007

description: The addition of an oligosaccharide elicitor results in a series of coordinated events leading to stimulation of various morphological and/or physiological responses in Penicillium chrysogenum. Whilst elicitation in P. chrysogenum has been reported and is now established, no scientific evidence has been put forward to explain the complex phenomenon behind the observations. To expand the potential of elicitation in fungi from laboratory to industrial scale it is essential to establish the potential generic nature of the elicitor’s effect and to provide concrete reasons for the changes observed. This work, serves as a starting point for the elucidation of some possible mechanisms. Mannan oligosaccharides (MO) derived from locust bean gum, and oligomannuronate (OM) from alginate were used in these studies. The effect of multiple addition of the same elicitor was investigated with a prospect that repeated addition would re-trigger the stimulation resulting in either maintenance of the penicillin G levels or enhancement of the production rate. However repeated addition of the same elicitor did not show any change in the production rate in comparison to single additions. Multiple additions of different elicitor types at different times and concentrations in a 5 L bioreactor showed an increase of 150% and 100% in the penicillin G production rate compared to the control and single elicitor addition cultures. The importance of structure-activity relationship of oligosaccharides in elicitation was investigated. In this study the reducing end of MO was reduced and the modified MO (MO-R) was used to study the structure-activity relationship. Addition of MO-R resulted in a 65% decrease in the elicitor activity, but did not eliminate the ability of the oligosaccharide to enhance the production of penicillin G when compared to the untreated oligosaccharides. The effect of single and multiple elicitor addition was also studied at the transcriptional level and showed that the transcript copy number in the elicited cultures was significantly higher (p <0.001) for the three major penicillin G biosynthetic genes (pcbAB, pcbC and penDE) in comparison to the control cultures. The effect of elicitor addition on the cytosolic calcium level was investigated. A fluorescent method was developed that provides a dynamic and reliable technique for the analysis of cytosolic calcium changes. The addition of elicitors showed a significant increase in the cytosolic Ca2+ compared to control cultures to which no elicitor was added (p < 0.001). The results found in this work aim to bring forward an understanding of the mechanism of action of elicitors in fungal cells.
Structural, electronic, and optical properties of the C-C complex in bulk silicon from first principles
Creators: name: Timerkaeva, Dilyara
name: Attaccalite, Claudio
name: Brenet, Gilles
name: Caliste, Damien
name: Pochet, Pascal
Publisher: name: arXiv
Year: 2017
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The structure of the CiCs complex in silicon has long been the subject of debate. Numerous theoretical and experimental studies have attempted to shed light on the properties of these defects that are at the origin of the light emitting G-center. These defects are relevant for applications in lasing, and it would be advantageous to control their formation and concentration in bulk silicon. It is therefore essential to understand their structural and electronic properties. In this paper, we present the structural, electronic, and optical properties of four possible configurations of the CiCs complex in bulk silicon, namely the A-, B-, C-, and D-forms. The configurations were studied by density functional theory (DFT) and many-body perturbation theory (MBPT). Our results suggest that the C-form was misinterpreted as a B-form in some experiments. Our optical investigation also tends to exclude any contribution of A- and B-forms to light emission. Taken together, our results suggest that the C-form could play an important role in heavily carbon-doped silicon.