cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Axion excursions of the landscape during inflation
Creators: name: Palma, Gonzalo A.
name: Riquelme, Walter
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: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Because of their quantum fluctuations, axion fields had a chance to experience field excursions traversing many minima of their potentials during inflation. We study this situation by analyzing the dynamics of an axion-spectator field $ψ$, present during inflation, with a periodic potential given by $v(ψ) = Λ^4 [1 - \cos (ψ/ f)]$. By assuming that the vacuum expectation value of the field is stabilized at one of its minima, say $ψ= 0$, we compute every $n$-point correlation function of $ψ$ up to first order in $Λ^4$ using the in-in formalism. This computation allows us to identify the distribution function describing the probability of measuring $ψ$ at a particular amplitude during inflation. Because $ψ$ is able to tunnel between the barriers of the potential, we find that the probability distribution function consists of a non-Gaussian multimodal distribution such that the probability of measuring $ψ$ at a minimum of $v(ψ)$ different from $ψ=0$ increases with time. As a result, at the end of inflation, different patches of the Universe are characterized by different values of the axion field amplitude, leading to important cosmological phenomenology: (a) Isocurvature fluctuations induced by the axion at the end of inflation could be highly non-Gaussian. (b) If the axion defines the strength of standard model couplings, then one is led to a concrete realization of the multiverse. (c) If the axion corresponds to dark matter, one is led to the possibility that, within our observable Universe, dark matter started with a nontrivial initial condition, implying novel signatures for future surveys.
description: 7 pages, 2 figures. v2: references added, improved discussion
Prabhakar-like fractional viscoelasticity
Creators: name: Giusti, Andrea
name: Colombaro, Ivano
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mathematical Physics (math-ph)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences
subject: 33E12, 44A10, 76A10, 26A33

description: The aim of this paper is to present a linear viscoelastic model based on Prabhakar fractional operators. In particular, we propose a modification of the classical fractional Maxwell model, in which we replace the Caputo derivative with the Prabhakar one. Furthermore, we also discuss how to recover a formal equivalence between the new model and the known classical models of linear viscoelasticity by means of a suitable choice of the parameters in the Prabhakar derivative. Moreover, we also underline an interesting connection between the theory of Prabhakar fractional integrals and the recently introduced Caputo-Fabrizio differential operator.
description: 9 pages
title: Effect of shock pressure on the Verwey transition in magnetite: Modelling of the magnetic susceptibility with various distributions of transition temperatures
Creators: name: Fuchs, Helena
name: Schilling, Frank R.
name: Kontny, Agnes
Publisher: name: Deutsche Geologische Gesellschaft - Geologische Vereinigung e.V. (DGGV)
Year: 2022

description:
Magnetite occurs as an accessory mineral in many rocks. It shows a strong ferrimagnetic behavior with a phase transition at about 120 K (Verwey transition temperature), which causes a strong increase in magnetic susceptibility by warming through the transition. The transition temperature shows a complex dependence on chemical composition, oxidation and internal stresses and was suggested as an indicator of shock pressures in terrestrial impact structures [e.g., 1].

Here, susceptibility curves were modelled between 80 and 200 K assuming probabilistically distributed transition temperatures representing variations in local stress fields. An improved version of a previously presented model was used [2]. The model was applied to susceptibility curves of magnetite-rich iron ore shocked at 5, 10, 20 and 30 GPa in laboratory experiments with subsequent heat treatment [3,4]. The results show a clear change from a sharp normal distribution of transition temperatures in unstressed ore towards a broad heavy-tailed Lorentz distribution in highly stressed samples. This behavior can be related to shock-induced dislocations. The distribution of transition temperatures in stressed ore indicates interactions between magnetic domains and could be useful e.g. for the distinction between stress and oxidation effects on the Verwey transition of rocks.

[1] Carporzen et al. (2006), Earth Planet Sci Lett 251, 305-317; [2] Fuchs et al. (2019), AGU Fall Meeting 2019, GP23B-0790; [3] Reznik et al. (2016), Geochem Geophys Geosyst 17, 2374-2393; [4] Kontny et al. (2018), Geochem Geophys Geosyst 19, 921-931.
The role of quantum correlations in Cop and Robber game
Creators: name: Glos, Adam
name: Miszczak, Jarosław Adam
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Physics (quant-ph)
subject: Discrete Mathematics (cs.DM)
subject: Computer Science and Game Theory (cs.GT)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences
subject: G.2.2
subject: 05C57 (Primary), 91A46, 81P40 (Secondary)

description: We introduce and study quantized versions of Cop and Robber game. We achieve this by using graph-preserving quantum operations, which are the quantum analogues of stochastic operations preserving the graph. We provide the tight bound for the number of operations required to reach the given state. By extending them to the controlled operations, we define a quantum-controlled Cop and Robber game, which expands the classical Cop and Robber game, as well as the classically controlled quantum Cop and Robber game. In contrast to the typical scheme for introducing quantum games, we assume that both parties can utilise full information about the opponent's strategy. We show that the utilisation of the full knowledge about the opponent's state does not provide the advantage. Moreover, the chances of catching the Robber decrease for classical cop-win graphs. This result does not depend on the chosen model of evolution. On the other hand, the possibility to execute controlled quantum operations allows catching the Robber on almost all classical cop-win graphs. By this, we demonstrate that it is necessary to enrich the structure of correlations between the players' systems to provide a non-trivial quantized Cop and Robber game. Thus the quantum controlled operations offer a significant advantage over the classically controlled quantum operations.
description: 15 pages, 2 tikz figures
Calculation of Gamow-Teller and Two-Neutrino Double-Beta Decay Properties for 130Te and 136Xe with a realistic nucleon-nucleon potential
Creators: name: Coraggio, L.
name: De Angelis, L.
name: Fukui, T.
name: Gargano, A.
name: Itaco, N.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We report on the calculation of Gamow-Teller and double-beta decay properties for nuclei around 132Sn within the framework of the realistic shell model. The effective shell-model Hamiltonian and Gamow-Teller transition operator are derived by way of many-body perturbation theory, without resorting to empirical effective quenching factor for the Gamow-Teller operator. The results are then compared with the available experimental data, in order to establish the reliability of our approach. This is a mandatory step, before we apply the same methodology, in forthcoming studies, to the calculation of the neutrinoless double-beta decay nuclear matrix element for nuclei that are currently considered among the best candidates for the detection of this process.
description: 10 pages, 13 figures, 6 tables, 1 appendix, to be published in Physical Review C
Cluster Formation and Percolation in Ethanol-Water mixtures
Creators: name: Gereben, Orsolya
name: Pusztai, László
Publisher: name: arXiv
Year: 2017
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: Results of systematic molecular dynamics studies of ethanol-water mixtures, over the entire concentration range, were reported previously to agree with experimental X-ray diffraction data. These simulated systems are analyzed in this work to examine cluster formation and percolation, using four different hydrogen bond definitions. Percolation analyses revealed that each mixture (even the one containing 80 mol % ethanol) is above the 3D percolation threshold, with fractal dimensions, df, between 2.6 to 2.9, depending on concentration. Monotype water cluster formation was also studied in the mixtures: 3D water percolation can be found in systems with less than 40 mol % ethanol, with fractal dimensions between 2.53 and 2.84. These observations can be put in parallel with experimental data on some thermodynamic quantities, such as the excess partial molar enthalpy and entropy.
$g$-factor engineering with InAsSb alloys toward zero band gap limit
Creators: name: Jiang, Yuxuan
name: Ermolaev, Maksim
name: Moon, Seongphill
name: Kipshidze, Gela
name: Belenky, Gregory
name: Svensson, Stefan
name: Ozerov, Mykhaylo
name: Smirnov, Dmitry
name: Jiang, Zhigang
name: Suchalkin, Sergey
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Band gap is known as an effective parameter for tuning the Lande $g$-factor in semiconductors and can be manipulated in a wide range through the bowing effect in ternary alloys. In this work, using the recently developed virtual substrate technique, high-quality InAsSb alloys throughout the whole Sb composition range are fabricated and a large $g$-factor of $g\approx -90$ at the minimum band gap of $\sim 0.1$ eV, which is almost twice that in bulk InSb is found. Further analysis to the zero gap limit reveals a possible gigantic $g$-factor of $g\approx -200$ with a peculiar relativistic Zeeman effect that disperses as the square root of magnetic field. Such a $g$-factor enhancement toward the narrow gap limit cannot be quantitatively described by the conventional Roth formula, as the orbital interaction effect between the nearly triply degenerated bands becomes the dominant source for the Zeeman splitting. These results may provide new insights into realizing large $g$-factors and spin polarized states in semiconductors and topological materials.
Time crystal behavior of excited eigenstates
Creators: name: Syrwid, Andrzej
name: Zakrzewski, Jakub
name: Sacha, Krzysztof
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Physics (quant-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: In analogy to spontaneous breaking of continuous space translation symmetry in the process of space crystal formation, it was proposed that spontaneous breaking of continuous time translation symmetry could lead to time crystal formation. In other words, a time-independent system prepared in the energy ground state is expected to reveal periodic motion under infinitely weak perturbation. In the case of the system proposed originally by Frank Wilczek, spontaneous breaking of time translation symmetry can not be observed if one starts with the ground state. We point out that the symmetry breaking can take place if the system is prepared in an excited eigenstate. The latter can be realized experimentally in ultra-cold atomic gases. We simulate the process of the spontaneous symmetry breaking due to measurements of particle positions and analyze the lifetime of the resulting symmetry broken state.
description: 5 pages, 3 figures, minor changes (version accepted for publication in Phys. Rev. Lett.)
Semiclassics in a system without classical limit: The few-body spectrum of two interacting bosons in one dimension
Creators: name: Geiger, Benjamin
name: Urbina, Juan-Diego
name: Hummel, Quirin
name: Richter, Klaus
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We present a semiclassical study of the spectrum of a few-body system consisting of two short-range interacting bosonic particles in one dimension, a particular case of a general class of integrable many-body systems where the energy spectrum is given by the solution of algebraic transcendental equations. By an exact mapping between $δ$-potentials and boundary conditions on the few-body wave functions, we are able to extend previous semiclassical results for single-particle systems with mixed boundary conditions to the two-body problem. The semiclassical approach allows us to derive explicit analytical results for the smooth part of the two-body density of states that are in excellent agreement with numerical calculations. It further enables us to include the effect of bound states in the attractive case. Remarkably, for the particular case of two particles in one dimension, the discrete energy levels obtained through a requantization condition of the smooth density of states are essentially in perfect agreement with the exact ones.
description: 10 pages, 8 figures, minor changes and corrections to match published verson in Physical Review E
Strong Correlation Effects on Surfaces of Topological Insulators via Holography
Creators: name: Seo, Yunseok
name: Song, Geunho
name: Sin, Sang-Jin
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We investigate effects of strong correlation on the surface state of topological insulator (TI). We argue that electrons in the regime of crossover from weak anti-localization to weak localization, are strongly correlated and calculate magneto-transport coefficients of TI using gauge gravity principle. Then, we examine, magneto-conductivity (MC) formula and find excellent agreement with the data of chrome doped Bi$_{2}$Te$_{3}$ in the crossover regime. We also find that cusp-like peak in MC at low doping is absent, which is natural since quasi-particles disappear due to the strong correlation.
description: 5 pages, 6 figures, figure and reference added, discussion on the result added
Cu-Sb dumbbell arrangement in the spin-orbital liquid candidate Ba$_3$CuSb$_2$O$_9$
Creators: name: Altmeyer, Michaela
name: Mila, Frederic
name: Smerald, Andrew
name: Valenti, Roser
Publisher: name: arXiv
Year: 2017
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The absence of both spin freezing and of a static Jahn-Teller effect have lead to the proposition that Ba$_3$CuSb$_2$O$_9$ is a quantum spin-orbital liquid. However, theoretical understanding of the microscopic origin of this behavior has been hampered by a lack of consensus on the lattice structure. Cu ions have been proposed to realize either a triangular lattice, a short-range ordered honeycomb lattice or a disordered lattice with stripelike correlations. Here we analyze the stability of idealized versions of these arrangements using density functional theory. We find stripe order of Cu ions to be energetically favored, hinting towards stripelike local Cu-Cu arrangements, while long-range order is presumably hindered due to disorder effects. Furthermore, we find evidence of significant interlayer interactions between Cu-Sb dumbbells, which affects the out-of-plane arrangement. Analysis of the relaxed crystal structures, electronic properties and tight-binding parameters provides clues as to the nature of the Jahn-Teller distortions.
description: 6 pages, 6 figures
An Analytic Method to Determine the Optimal Time for the Induction Phase of Anesthesia
Creators: name: Zaitri, Mohamed A.
name: Silva, Cristiana J.
name: Torres, Delfim F. M.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Optimization and Control (math.OC)
subject: FOS: Mathematics
subject: 49M05, 49N90, 92C45

description: We obtain an analytical solution for the time-optimal control problem in the induction phase of anesthesia. Our solution is shown to align numerically with the results obtained from the conventional shooting method. The induction phase of anesthesia relies on a pharmacokinetic/pharmacodynamic (PK/PD) model proposed by Bailey and Haddad in 2005 to regulate the infusion of propofol. In order to evaluate our approach and compare it with existing results in the literature, we examine a minimum-time problem for anesthetizing a patient. By applying the Pontryagin minimum principle, we introduce the shooting method as a means to solve the problem at hand. Additionally, we conducted numerical simulations using the MATLAB computing environment. We solve the time-optimal control problem using our newly proposed analytical method and discover that the optimal continuous infusion rate of the anesthetic and the minimum required time for transition from the awake state to an anesthetized state exhibit similarity between the two methods. However, the advantage of our new analytic method lies in its independence from unknown initial conditions for the adjoint variables.
description: This is a preprint of a paper whose final and definite form is published Open Access in 'Axioms' at [https://doi.org/10.3390/axioms12090867]
Paired states in half-filled Landau levels
Creators: name: Milovanović, M. V.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We discuss monolayer and bilayer quantum Hall systems in which each layer is a half-filled Landau level (LL) system. In the mean field approximation of the Son's formalism there is a common pairing structure that underlines the possibilities for paired ground states in both systems. We argue that the particle-hole (PH) Pfaffian state in the (particle-hole symmetric) half-filled LL of a monolayer, and analogous state in the PH symmetric bilayer (in which each layer is half-filled LL) can be considered as {\em critical states} i.e. states that cannot describe a phase under PH symmetry. We point out that the inclusion of a PH symmetry breaking (like LL mixing) may stabilize the PH Pfaffian in a monolayer. In the bilayer case, in numerical experiments on a sphere, by choosing the PH symmetric shift, we can stabilize the interlayer correlated (111) excitonic state or critical state, for any distance between the layers, but in general, with no bias, the evolution of the bilayer includes other phases.
description: 9 pages, rewritten, published version with important conclusions
Global Stabilization of Triangular Systems with Time-Delayed Dynamic Input Perturbations
Creators: name: Krishnamurthy, Prashanth
name: Khorrami, Farshad
Publisher: name: arXiv
Year: 2017
Subjects: subject: Optimization and Control (math.OC)
subject: Systems and Control (eess.SY)
subject: FOS: Mathematics
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: A control design approach is developed for a general class of uncertain strict-feedback-like nonlinear systems with dynamic uncertain input nonlinearities with time delays. The system structure considered in this paper includes a nominal uncertain strict-feedback-like subsystem, the input signal to which is generated by an uncertain nonlinear input unmodeled dynamics that is driven by the entire system state (including unmeasured state variables) and is also allowed to depend on time delayed versions of the system state variable and control input signals. The system also includes additive uncertain nonlinear functions, coupled nonlinear appended dynamics, and uncertain dynamic input nonlinearities with time-varying uncertain time delays. The proposed control design approach provides a globally stabilizing delay-independent robust adaptive output-feedback dynamic controller based on a dual dynamic high-gain scaling based structure.
description: 2017 IEEE International Carpathian Control Conference (ICCC)
An entropy for groups of intermediate growth
Creators: name: Kalogeropoulos, Nikolaos
Publisher: name: arXiv
Year: 2017
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: One of the few accepted dynamical foundations of non-additive "non-extensive") statistical mechanics is that the choice of the appropriate entropy functional describing a system with many degrees of freedom should reflect the rate of growth of its configuration or phase space volume. We present an example of a group, as a metric space, that may be used as the phase space of a system whose ergodic behavior is statistically described by the recently proposed $δ$-entropy. This entropy is a one-parameter variation of the Boltzmann/Gibbs/Shannon functional and is quite different, in form, from the power-law entropies that have been recently studied. We use the first Grigorchuk group for our purposes. We comment on the connections of the above construction with the conjectured evolution of the underlying system in phase space.
description: 19 pages, No figures, LaTeX2e. Version 2: change of affiliation, addition of acknowledgement. Accepted for publication to "Advances in Mathematical Physics"
Transmission losses in optical qubits for controlled teleportation
Creators: name: Medina, I.
name: Semião, F. L.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In this work, we investigate the controlled teleportation protocol using optical qubits within the single-rail logic. The protocol makes use of an entangled tripartite state shared by the controller and two further parties (users) who will perform standard teleportation. The goal of the protocol is to guarantee that the teleportation is successful only with the permission of the controller. Optical qubits based on either superpositions of vacuum and single-photon states or superposition of coherent states are employed here to encode a tripartite maximal slice state upon which the protocol is based. We compare the performances of these two encodings under losses which are present when the qubits are guided through an optical fiber to the users. Finally, we investigate the non-locality of the shared tripartite state to see whether or not it impacts the efficiency of the protocol.
description: 8 pages, 6 figures
Análise de dados de satélite na prospeção geológica: contribuição da deteção remota na geologia
Creators: name: Gonçalo, Rodrigues
Publisher: name: Zenodo
Year: 2024
Subjects: deteção remota
análise de dados
prospeção
satélite

description: Relatório de Estágio para a conclusão do grau de Licenciatura em Geologia (Faculdade de Ciências da Universidade do Porto) apresentado no ano letivo 2022-2023. Este relatório de estágio foi realizado no enquadramento do projeto Horizon Europe - S34I. O conteúdo é da inteira responsabilidade do autor.

Internship report for completion of the Bachelor's Degree in Geology (Faculty of Sciences of the University of Porto) presented in the academic year 2022-2023. This internship report was carried out within the scope of the Horizon Europe - S34I project. The content is the sole responsibility of the author.
Low-Quality Training Data Only? A Robust Framework for Detecting Encrypted Malicious Network Traffic
Creators: name: Qing, Yuqi
name: Yin, Qilei
name: Deng, Xinhao
name: Chen, Yihao
name: Liu, Zhuotao
name: Sun, Kun
name: Xu, Ke
name: Zhang, Jia
name: Li, Qi
Publisher: name: arXiv
Year: 2023
Subjects: subject: Cryptography and Security (cs.CR)
subject: FOS: Computer and information sciences

description: Machine learning (ML) is promising in accurately detecting malicious flows in encrypted network traffic; however, it is challenging to collect a training dataset that contains a sufficient amount of encrypted malicious data with correct labels. When ML models are trained with low-quality training data, they suffer degraded performance. In this paper, we aim at addressing a real-world low-quality training dataset problem, namely, detecting encrypted malicious traffic generated by continuously evolving malware. We develop RAPIER that fully utilizes different distributions of normal and malicious traffic data in the feature space, where normal data is tightly distributed in a certain area and the malicious data is scattered over the entire feature space to augment training data for model training. RAPIER includes two pre-processing modules to convert traffic into feature vectors and correct label noises. We evaluate our system on two public datasets and one combined dataset. With 1000 samples and 45% noises from each dataset, our system achieves the F1 scores of 0.770, 0.776, and 0.855, respectively, achieving average improvements of 352.6%, 284.3%, and 214.9% over the existing methods, respectively. Furthermore, We evaluate RAPIER with a real-world dataset obtained from a security enterprise. RAPIER effectively achieves encrypted malicious traffic detection with the best F1 score of 0.773 and improves the F1 score of existing methods by an average of 272.5%.
Quasilinear observables in dark energy cosmologies
Creators: name: Rampf, Cornelius
name: Villa, Eleonora
name: Amendola, Luca
Publisher: name: arXiv
Year: 2017
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: What are the fundamental limitations of reconstructing the properties of dark energy, given cosmological observations in the quasilinear regime in a range of redshifts, to be as precise as required? The aim of this paper is to address this question by constructing model-independent observables, whilst completely ignoring practical problems of real-world observations. Non-Gaussianities already present in the initial conditions are not directly accessible from observations, because of a perfect degeneracy with the non-Gaussianities arising from the nonlinear matter evolution in generalized dark energy models. By imposing a specific set of evolution equations that should cover a range of dark energy cosmologies, we however find a constraint equation for the linear structure growth rate $f_1$ expressed in terms of model-independent observables. Entire classes of dark energy models which do not satisfy this constraint equation could be ruled out, and for models satisfying it we could reconstruct e.g. the nonlocal bias parameters $b_1$ and $b_2$.
description: v1: 12 pages; v2: 14 pages, title changed, added references and a new section about theoretical limitations. v2 matches published version in PRD
Substrate Integrated Waveguide-Dielectric Resonator Antenna for Future Wireless Communication
Creators: name: Kumar, Pradeep
Publisher: name: figshare
Year: 2022
Subjects: subject: 100501 Antennas and Propagation
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: A substrate integrated Waveguide (SIW) fed rectangular shaped Dielectric Resonator Antenna (DRA) is proposed for application in the D-Band frequency regime. The Dielectric Resonator (DR) is designed to operate in higher order modes. A rectangular shaped narrow slot is used to excite the DR element, leading to multiple resonances. The resulting structure is a multi-resonant antenna operating at six frequencies at 123.64 GHz, 125.76 GHz, 127.4 GHz, 129.9 GHz, 134.9 GHz and 137.7 GHz frequencies. These are identified as TE10δ1, TE7δ5, TEδ31, TEδ25, TEδ31 and TEδ35 modes of operation of the resonator, respectively. These resonances are merged to achieve a-10 dB impedance bandwidth ranging between 122.58 GHz and 139.51 GHz, equivalent to 13.4% at a center frequency of 125.76 GHz. Moreover, the antenna possess stable radiation pattern in the broadband direction, across the entire frequency band of operation. Simulation results show that the antenna has a peak gain of 12.3 dBi, a maximum directivity of 13.14 dBi and a maximum efficiency of 84% at a frequency of 126 GHz. Simulated results show that the proposed design has potential and suitability for utilization in future wireless communications.
Naturalness, dark matter, and the muon anomalous magnetic moment in supersymmetric extensions of the standard model with a pseudo-Dirac gluino
Creators: name: Li, Chuang
name: Zhu, Bin
name: Li, Tianjun
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We study the naturalness, dark matter, and muon anomalous magnetic moment in the Supersymmetric Standard Models (SSMs) with a pseudo-Dirac gluino (PDGSSMs) from hybrid $F-$ and $D-$term supersymmetry (SUSY) breakings. To obtain the observed dark matter relic density and explain the muon anomalous magnetic moment, we find that the low energy fine-tuning measures are larger than about 30 due to strong constraints from the LUX and PANDAX experiments. Thus, to study the natural PDGSSMs, we consider multi-component dark matter and then the relic density of the lighest supersymmetric particle (LSP) neutralino is smaller than the correct value. We classify our models into six kinds: (i) Case A is a general case, which has small low energy fine-tuning measure and can explain the anomalous magnetic moment of the muon; (ii) Case B with the LSP neutralino and light stau coannihilation; (iii) Case C with Higgs funnel; (iv) Case D with Higgsino LSP; (v) Case E with light stau coannihilation and Higgsino LSP; (vi) Case F with Higgs funnel and Higgsino LSP. We study these Cases in details, and show that our models can be natural and consistent with the LUX and PANDAX experiments, as well as explain the muon anomalous magnetic moment. In particular, all these cases except the stau coannihilation can even have low energy fine-tuning measures around 10.
description: 19 pages, 18 figures
Sgoldstino-less inflation and low energy SUSY breaking
Creators: name: Argurio, Riccardo
name: Coone, Dries
name: Heurtier, Lucien
name: Mariotti, Alberto
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We assess the range of validity of sgoldstino-less inflation in a scenario of low energy supersymmetry breaking. We first analyze the consistency conditions that an effective theory of the inflaton and goldstino superfields should satisfy in order to be faithfully described by a sgoldstino-less model. Enlarging the scope of previous studies, we investigate the case where the effective field theory cut-off, and hence also the sgoldstino mass, are inflaton-dependent. We then introduce a UV complete model where one can realize successfully sgoldstino-less inflation and gauge mediation of supersymmetry breaking, combining the alpha-attractor mechanism and a weakly coupled model of spontaneous breaking of supersymmetry. In this class of models we find that, given current limits on superpartner masses, the gravitino mass has a lower bound of the order of the MeV, i.e. we cannot reach very low supersymmetry breaking scales. On the plus side, we recognize that in this framework, one can derive the complete superpartner spectrum as well as compute inflation observables, the reheating temperature, and address the gravitino overabundance problem. We then show that further constraints come from collider results and inflation observables. Their non trivial interplay seems a staple feature of phenomenological studies of supersymmetric inflationary models.
description: 40 pages, 4 figures. v2: minor clarifications added (as published in JCAP)
title: Behavior of chemically zoned acicular mullite fibers annealed at high temperature
Creators: name: Igami, Yohei
name: Birkenstock, Johannes
name: Fischer, Reinhard X.
name: Schneider, Hartmut
Publisher: name: Deutsche Geologische Gesellschaft - Geologische Vereinigung e.V. (DGGV)
Year: 2022

description:
The synthetic analogue of the rare mineral mullite (solid solution VIAl2IV[Al2+2xSi2-2x]O10-x) is widely used in ceramics as “3/2-mullite” (x~0.25), whereas single crystals grown from melt are “2/1-mullites” (x~0.4) [1].

The investigated acicular mullite ceramic consists of single-crystalline fibers with high-Al mullite (M1) in the core and low-Al mullite (M2) in the rim [2,3], appearing as two distinct mullite phases in powder XRD patterns [2]. On annealing the as-prepared sample at 1550°C (24, 96, 192 and 384 h) the two zones gradually merge into one homogeneous phase [2]. Here, we present the details of this merging, investigating cross sections of fibers via TEM.

Observed changes in a) width of the transition zone, b) relative lattice orientations of the two zones and c) lattice parameter a document progressive homogenization of the mullite, which is complete after 384h. Concurrently, we observed Si-rich, round to rectangular amorphous regions, probably from partial melting, most strikingly after 384 h. An increasing amount of Si-rich glass phase with annealing time would explain the overall increase of average Al-content in mullite which we observed in our XRD data [2].

We thank Prof. K.T. Faber (NW University, Evanston, IL/USA) for the samples, and the DFG for funding (Grant FI442/24-1).

[1] R.X. Fischer & H. Schneider (2005), in Mullite (eds. H. Schneider, S. Komarneni), Weinheim: Wiley-VCH 1-46

[2] J. Birkenstock, Y. Igami, R.X. Fischer & H. Schneider (2019), Abstract GeoMünster 2019

[3] A.J. Pyzik, C.S. Todd & C. Han (2008), J. Eur. Cer. Soc. 28, 383-391
Non-interacting central site model: localization and logarithmic entanglement growth
Creators: name: Hetterich, Daniel
name: Serbyn, Maksym
name: Domínguez, Fernando
name: Pollmann, Frank
name: Trauzettel, Björn
Publisher: name: arXiv
Year: 2017
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We investigate the stationary and dynamical behavior of an Anderson localized chain coupled to a single central bound state. The coupling to the central site partially dilutes the Anderson localized peak towards the nearly resonant sites. In particular, the number of resonantly coupled sites remains finite in the thermodynamic limit. This is further supported by a multifractal analysis of eigenstates that shows the frozen spectrum of fractal dimension, which is characteristic for localized phases in models with power-law hopping. Although the well-known Fano-resonance problem is seemingly similar to our system, it fails to describe it because of the absence of level repulsion within the energy spectrum. For weak coupling strengths to the central site, we identify a regime with a logarithmic in time transport of particles and information.
description: 10 pages, 7 figures
Lepton flavor violating Higgs boson decays in seesaw models: new discussions
Creators: name: Thao, N. H.
name: Hue, L. T.
name: Hung, H. T.
name: Xuan, N. T.
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The lepton flavor violating decay of the Standard Model-like Higgs boson (LFVHD), h->μτ, is discussed in seesaw models at the one-loop level. Based on particular analytic expressions of Passarino-Veltman functions, the two unitary and 't Hooft Feynman gauges are used to compute the branching ratio of LFVHD and compare with results reported recently. In the minimal seesaw (MSS) model, the branching ratio was investigated in the whole valid range 10^{-9}-10^{15} GeV of new neutrino mass scale m_{n_6}. Using the Casas-Ibarra parameterization, this branching ratio enhances with large and increasing m_{n_6}. But the maximal value can reach only order of 10^{-11}. Interesting relations of LFVHD predicted by the MSS and inverse seesaw (ISS) model are discussed. The ratio between two LFVHD branching ratios predicted by the ISS and MSS is simply m^2_{n_6}μ^{-2}_X, where μ_X is the small neutrino mass scale in the ISS. The consistence between different calculations is shown precisely from analytical approach.
description: 4 figures, 26 pages, some analytic formulas and statements are corrected. Main results are unchanged. New references added. Version published in NPB
Detecting Violations of Differential Privacy for Quantum Algorithms
Creators: name: Guan, Ji
name: Fang, Wang
name: Huang, Mingyu
name: Ying, Mingsheng
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: Cryptography and Security (cs.CR)
subject: Machine Learning (cs.LG)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Quantum algorithms for solving a wide range of practical problems have been proposed in the last ten years, such as data search and analysis, product recommendation, and credit scoring. The concern about privacy and other ethical issues in quantum computing naturally rises up. In this paper, we define a formal framework for detecting violations of differential privacy for quantum algorithms. A detection algorithm is developed to verify whether a (noisy) quantum algorithm is differentially private and automatically generate bugging information when the violation of differential privacy is reported. The information consists of a pair of quantum states that violate the privacy, to illustrate the cause of the violation. Our algorithm is equipped with Tensor Networks, a highly efficient data structure, and executed both on TensorFlow Quantum and TorchQuantum which are the quantum extensions of famous machine learning platforms -- TensorFlow and PyTorch, respectively. The effectiveness and efficiency of our algorithm are confirmed by the experimental results of almost all types of quantum algorithms already implemented on realistic quantum computers, including quantum supremacy algorithms (beyond the capability of classical algorithms), quantum machine learning models, quantum approximate optimization algorithms, and variational quantum eigensolvers with up to 21 quantum bits.
Scaling maps of $s$-ordered quasiprobabilities are either nonpositive or completely positive
Creators: name: Ivan, J. Solomon
name: Sabapathy, Krishna Kumar
name: Simon, R.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Continuous-variable systems in quantum theory can be fully described through any one of the ${\rm s}$-ordered family of quasiprobabilities $Λ_{\rm s}(α)$, ${\rm s} \in [-1,1]$. We ask for what values of $({\rm s}, a)$ is the scaling map $Λ_{\rm s}(α) \rightarrow a^{-2} Λ_{\rm s}(a^{-1}α)$ a positive map? Our analysis based on a duality we establish settles this issue (i) the scaling map generically fails to be positive, showing that there is no useful entanglement witness of the scaling type beyond the transpose map, and (ii) in the two particular cases $({\rm s}=1, |a| \leq 1)$ and $({\rm s}=-1, |a| \geq 1)$, and only in these two non-trivial cases, the map is not only positive but also completely positive as seen through the noiseless attenuator and amplifier channels. We also present a `phase diagram' for the behaviour of the scaling maps in the ${\rm s}-a$ parameter space with regard to its positivity, obtained from the viewpoint of symmetric-ordered characteristic functions. This also sheds light on similar diagrams for the practically relevant attenuation and amplification maps with respect to the noise parameter, especially in the range below the complete-positivity (or quantum-limited) threshold.
description: v2: 7 pages, 4 figs, minor changes, close to published version
title: Fossilization of Triassic marine reptile bones from southwest China – bone diagenesis at elevated temperature
Creators: name: Li, Qiang
name: Tomaschek, Frank
name: Gäb, Fabian
name: Sander, P. Martin
Publisher: name: Deutsche Geologische Gesellschaft - Geologische Vereinigung e.V. (DGGV)
Year: 2022

description:
The preservation of fossils over long periods of geological history usually has special characteristics, and the specific conditions for successful fossilization have not been established yet. Triassic bones from SW China are characterized by an exceptionally broad variation in the style of preservation. This region presents a perfect natural lab for the study of conditions advantageous for bone preservation. Twenty-five specimens of marine reptiles from the Middle to Late Triassic black shales were sampled and examined in petrographic thin sections, by Raman spectroscopy and wavelength-dispersive X-ray spectroscopy. Our results revealed evidence that the bones were heated, possibly by hydrothermal fluids or by regional geological events, and we observed fluorite in fossil bone for the first time. We discriminate five stages of bone alteration: 1) no alteration beyond diagenetic mineral precipitation in the bone porosity; 2) weak alteration of apatite and migration of kerogen from the shale into the fossil bone; 3) formation of authigenic fluorite needles; 4) Recrystallization of bone apatite to idiomorphic apatite while bone structure is still present; 5) complete loss of bone structure and replacement by idiomorphic apatite. Systematic carbon Raman thermometry returns temperatures up to 150-180°C, indicating that loss of histological information might be linked to temperatures near to low-grade metamorphism. This study provides reference data for different stages of bone alteration, which is important for the study of bone diagenetic processes in dependence of higher than near-surface temperatures.
Psalm reading and the lyric sequence in Renaissance England
Creators: name: Specland, Jeremy
Publisher: name: No Publisher Supplied
Year: 2022

description: This dissertation argues that daily reading practices emerging from the Protestant Reformation made the psalms a model for the lyric sequence during the first century of the form’s appearance in English, from 1560 to 1660. The Book of Psalms (or “psalter,” as it was interchangeably called) was Renaissance England’s most popular text, sung in every church service, read morning and evening in the home, and circulated in the era’s many printed bibles, liturgies, and stand-alone psalters. Proponents of English Reformation sought to give lay readers access to the 150 psalms of the psalter through reading methods that they prescribed in the commentaries and textual apparatus of these abundant printed editions. Archival research demonstrates that two methods of psalm reading competed for dominance: selecting psalms by present occasion or reading sequentially according to a liturgical calendar. This competition lent two distinct poles to the period’s collections of original sonnets and other verse forms, now known as “lyric sequences.” On the model of the psalms, the sequences addressed in the dissertation—A Meditation of a penitent sinner (1560), Spenser’s Amoretti (1594), Shakespeare’s Sonnets (1609), and Herbert’s The Temple (1633)—present their poems as both discrete units answering to particular occasions and members of well-organized wholes unfolding over time. Although critics generally trace the formal features of the lyric sequence to the Italian poet Petrarch and his 366-poem Canzoniere (ca. 1327-68), the psalter provided Renaissance readers with an even more widespread collection of poems characterized by tension between part and whole. Attending to the English sequence’s specifically psalmic tension revises the form’s genealogy, showing how a 2,500-year-old ritual text shaped poetic practices still prevalent across the anglophone world today.
Boundary Conditions and Formation of Pure Spin Currents in Magnetic Field
Creators: name: Eliashvili, Merab
name: Tsitsishvili, George
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Schrödinger equation for an electron confined to a two-dimensional strip is considered in the presence of homogeneous orthogonal magnetic field. Since the system has edges, the eigenvalue problem is supplied by the boundary conditions (BC) aimed in preventing the leakage of matter away across the edges. In the case of spinless electrons the Dirichlet and Neumann BC are considered. The Dirichlet BC result in the existence of charge carrying edge states. For the Neumann BC each separate edge comprises two counterflow sub-currents which precisely cancel out each other provided the system is populated by electrons up to certain Fermi level. Cancelation of electric current is a good starting point for developing the spin-effects. In this scope we reconsider the problem for a spinning electron with Rashba coupling. The Neumann BC are replaced by Robin BC. Again, the two counterflow electric sub-currents cancel out each other for a separate edge, while the spin current survives thus modeling what is known as pure spin current -- spin flow without charge flow.
description: 9 pages, 5 figures
Black Holes, Dark Matter Spikes, and Constraints on Simplified Models with $t$-Channel Mediators
Creators: name: Sandick, Pearl
name: Sinha, Kuver
name: Yamamoto, Takahiro
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The density spike of dark matter (DM) in the subparsec region near the supermassive black hole at the Galactic Center can provide potentially observable gamma-ray signals coming from DM annihilations. Taking Fermi-$LAT$ data for the gamma-ray flux from the point source 3FGL J1745.6-2859c (Sgr A*), we calculate the resulting constraints on generic models of DM, allowing for the possibility of a non-negligible velocity-dependent component of the annihilation cross section. We consider a variety of selections for the astrophysical parameters that describe the spike profile and find that the gamma-ray flux is strongly dependent on these selections, particularly the modelling of spike depletion effects due to gravitational interactions with baryons, which affect the spike radius and steepness profile. We calculate constraints on the DM parameter space for both attenuated and idealized spikes, considering different choices for the steepness profiles in each case. We find that for the most conservative selection of parameters, corresponding to a depleted spike with an NFW cusp profile, the gamma-ray flux for a 100 GeV thermal relic is lower than current observational constraints by several orders of magnitude. For more optimistic choices of parameters corresponding to spikes that have not been attenuated, bounds on DM masses can be obtained for a variety of choices of steepness profiles. We then specialize to a class of simplified models of fermionic DM that annihilate dominantly through the $t-$channel exchange of two scalar mediators with arbitrary mixing angle $α$, and calculate the indirect detection constraints coming from the DM spike. Along the way, we discuss constraints on the astrophysical parameters describing the DM spike, taking the Galactic Center excess as a signal of DM annihilation.
description: 27 pages, 12 figures. Portions of text re-written, new figures added. Conclusions unchanged