cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Evading Lyth bound in models of quintessential inflation
Creators: name: Hossain, Md. Wali
name: Myrzakulov, R.
name: Sami, M.
name: Saridakis, Emmanuel N.
Publisher: name: arXiv
Year: 2014
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Quintessential inflation refers to an attempt to unify inflation and late-time cosmic acceleration using a single scalar field. In this letter we consider two different classes of quintessential inflation, one of which is based upon a Lagrangian with non-canonical kinetic term $k^2(ϕ)\partial^μϕ\partial_μϕ$ and a steep exponential potential while the second class uses the concept of steep brane world inflation. We show that in both cases the Lyth bound can be evaded, despite the large tensor-to-scalar ratio of perturbations. The post-inflationary dynamics is consistent with nucleosynthesis constraint in these cases.
description: 6 Latex pages, no figures, reference updated and typos corrected, To appear in PLB
Low-frequency gravitational wave memory from gamma-ray burst afterglows with energy injection
Creators: name: Huang, Bao-Quan
name: Liu, Tong
name: Xue, Li
name: Qi, Yan-Qing
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Ultrarelativistic gamma-ray burst (GRB) jets are strong gravitational wave (GW) sources with memory-type signals. The plateau (or shallow decay) phases driven by the energy injection might appear in the early X-ray afterglows of GRBs. In this paper, we investigate the GW signal as well as X-ray afterglow emission in the framework of GRB jets with energy injection, and both short- and long-duration GRBs are considered. We find that, regardless of the case, because of the antibeaming and time delay effects, a rising slope emerging in the waveform of GW signal due to the energy injection lags far behind the energy ejection, and the typical frequency of the characteristic amplitudes falls within a low-frequency region of $\sim10^{-4}-10^{-6} \,{\rm Hz}$; and we consider that the GW memory triggered by GRB jets with energy injection are previously unaware and the nearby GRBs with strong energy injection might disturb the measurement of the stochastic GW background. Such GW memory detection would provide a direct test for models of energy injection in the scenario of GRB jets.
description: 9 pages, 4 figures, accepted for publication in ApJ
Scattering nonlocality in quantum charge transport: Application to semiconductor nanostructures
Creators: name: Rosati, Roberto
name: Rossi, Fausto
Publisher: name: arXiv
Year: 2014
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Our primary goal is to provide a rigorous treatment of scattering nonlocality in semiconductor nanostructures. On the one hand, starting from the conventional density-matrix formulation and employing as ideal instrument for the study of the semiclassical limit the well-known Wigner-function picture, we shall perform a fully quantum-mechanical derivation of the space-dependent Boltzmann equation. On the other hand, we shall examine the validity limits of such semiclassical framework, pointing out, in particular, regimes where scattering-nonlocality effects may play a relevant role; to this end we shall supplement our analytical investigation with a number of simulated experiments, discussing and further expanding preliminary studies of scattering-induced quantum diffusion in GaN-based nanomaterials. As for the case of carrier-carrier relaxation in photoexcited semiconductors, our analysis will show the failure of simplified dephasing models in describing phonon-induced scattering nonlocality, pointing out that such limitation is particularly severe for the case of quasielastic dissipation processes.
description: 18 pages, 10 figures
Dynamic conditioning of two particle discrete-time quantum walks
Creators: name: Pegoraro, Federico
name: Held, Philip
name: Barkhofen, Sonja
name: Brecht, Benjamin
name: Silberhorn, Christine
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In real photonic quantum systems losses are an unavoidable factor limiting the scalability to many modes and particles, restraining their application in fields as quantum information and communication. For this reason, a considerable amount of engineering effort has been taken in order to improve the quality of particle sources and system components. At the same time, data analysis and collection methods based on post-selection have been used to mitigate the effect of particle losses. This has allowed for investigating experimentally multi-particle evolutions where the observer lacks knowledge about the system's intermediate propagation states. Nonetheless, the fundamental question how losses affect the behaviour of the surviving subset of a multi-particle system has not been investigated so far. For this reason, here we study the impact of particle losses in a quantum walk of two photons reconstructing the output probability distributions for one photon conditioned on the loss of the other in a known mode and temporal step of our evolution network. We present the underlying theoretical scheme that we have devised in order to model controlled particle losses, we describe an experimental platform capable of implementing our theory in a time multiplexing encoding. In the end we show how localized particle losses change the output distributions without altering their asymptotic spreading properties. Finally we devise a quantum civilization problem, a two walker generalisation of single particle recurrence processes.
description: 11 pages, 8 figures
Spherically symmetric Anti-de Sitter-like Einstein-Yang-Mills spacetimes
Creators: name: Lübbe, C.
name: Kroon, J. A. Valiente
Publisher: name: arXiv
Year: 2014
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The conformal field equations are used to discuss the local existence of spherically symmetric solutions to the Einstein-Yang-Mills system which behave asymptotically like the anti-de Sitter spacetime. By using a gauge based on conformally privileged curves we obtain a formulation of the problem in terms of an initial boundary value problem on which a general class of maximally dissipative boundary conditions can be discussed. The relation between these boundary conditions and the notion of mass on asymptotically anti-de Sitter spacetimes is analysed.
description: 31 pages, 2 figures. Analysis extended to include a Yang-Mills fields with non-vanishing magnetic part
title: Thesis on time
Creators: name: Pantelides, Leonidas
Publisher: name: University of Kent
Year: 2022

description: The concept of time is in some essential and non-trivial way tied up with the issue of "structure". But while there is reason discouraging us from saying that time itself is a structured specificity, (in the manner let's say of McTaggart), nevertheless in some way its meaning consists as a linguistic/conceptual substitute for the idea of structuration of non-tempora1 determinations. Philosophically, we are better off not saying that time pocesses "ontical being" - (to borrow a term from Heidegger) - ie. that time itself is a set of facts to be found "in the world". Yet, at the same time we can not say that time does not exist. What then might the correct manner be so that we can both account for its meaningful description and steer clear of contradictions? So, too, we must say that time is not (simply) an ontological commitment. If we did, we would have to decide on a priviledged starting-point, a set of most fundamental claims about the world which would serve as the grounds from which time is to be inferred. But if different choices would lead to different interpretations of time, on what basis should we account for an independent ontological status for time? In this way time remains bound thematically and is made an inexplicable horizon of whatever structures are assumed to constitute the world. Rather, we must philosophically assert that time meta-logically pre-dates and indeed grounds these logical functions of construing the world as either "factual" or "factical". This, time can do because it is what we might call an "onto-constitutive" function. In addition to the attempt to metaphysically clarify the manner of being of time, I have made specific proposals on and have suggested analyses of the multiple and varying ways that temporal determinations are articulated as modalities. This I let for the reader of the thesis to tackle if he so wishes. I must, however, mention one additional methodological implication so that this very sketchy synopsis of the argument can be rounded off.
Resolved CO(1-0) emission and gas properties in luminous dusty star forming galaxies at z=2-4
Creators: name: Stanley, F.
name: Jones, B. M.
name: Riechers, D. A.
name: Yang, C.
name: Berta, S.
name: Cox, P.
name: Bakx, T. J. L. C.
name: Cooray, A.
name: Dannerbauer, H.
name: Dye, S.
name: Hughes, D. H.
name: Ivison, R. J.
name: Jin, S.
name: Lehnert, M.
name: Neri, R.
name: Omont, A.
name: van der Werf, P.
name: Weiss, A.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present the results of a survey of CO(1-0) emission in 14 infrared luminous dusty star forming galaxies (DSFGs) at 2 < z < 4 with the NSF's Karl G. Jansky Very Large Array. All sources are detected in CO(1-0), with an ~1arcsec angular resolution. Seven sources show extended and complex structure. We measure CO luminosities of $(μ)L'_{CO(1-0)}=0.4-2.9x10^{11}$ K km s$^{-1}$ pc$^2$, and molecular gas masses of ($μ$)M$_{H2}$ = 1.3 - 8.6 x 10$^{11}$ Mo, where (μ) is the magnification factor. The derived molecular gas depletion times of t$_{\rm dep}$ = 40 - 460 Myr, cover the expected range of both normal star forming galaxies and starbursts. Comparing to the higher-J CO transitions previously observed for the same sources, we find CO temperature brightness ratios of r$_{32/10}$ = 0.4 - 1.4, r$_{43/10}$ = 0.4 - 1.7, and r$_{54/10}$ = 0.3 - 1.3. We find a wide range of CO spectral line energy distributions (SLEDs), in agreement with other high-z DSFGs, with the exception of three sources that are most comparable to the Cloverleaf and APM08279+5255. Based on radiative transfer modelling of the CO SLEDs we determine densities of n$_{H2}$ = 0.3 - 8.5 x 10$^3$ cm$^{-3}$ and temperatures of T$_K$ = 100 - 200 K. Lastly, four sources are detected in the continuum, three have radio emission consistent with their infrared derived star formation rates, while HerBS-70E requires an additional synchrotron radiation component from an active galactic nucleus. Overall, we find that even though the sample is similarly luminous in the infrared, by tracing the CO(1-0) emission a diversity of galaxy and excitation properties are revealed, demonstrating the importance of CO(1-0) observations in combination to higher-J transitions.
description: 25pages , 13 figures, Accepted for publication at ApJ
Searching Doubly Charged Leptons at Present and Future Colliders
Creators: name: Biondini, Simone
name: Panella, Orlando
name: Pancheri, Giulia
name: Srivastava, Yogendra
name: Fanò, Livio
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The production at the LHC of exotic excited leptons of charge $Q = +2e$ is considered. Such states are predicted in composite models with extended isospin multiplets ($I_{W}=1$ and $I_{W}=3/2$). The coupling among these doubly charged leptons and Standard Model fermions may occurs either via gauge or contact interactions. In the former case the decay channels are more constrained. We study the production cross section at the LHC of $L^{++}$ ($pp \rightarrow L^{++} \, \ell^{-}$) and focus on the leptonic signature deriving from the subsequent decays $L^{++} \rightarrow W^{+} \ell^{+} \rightarrow \ell^{+} \ \ell^{+} \, ν_l $. The invariant mass distribution of the like-sign dilepton exhibits a sharp end-point corresponding to excited doubly charged lepton mass $m^{*}$. A preliminary study for the production of doubly charged leptons at the future linear colliders, by considering the process $e^{-} e^{-} \rightarrow L_{e}^{--} \, ν_{e}$, is carried out. Both the contact and gauge interaction mechanisms are investigated and compared.
description: 8 pages, 4 figures, submitted as a proceeding for the LC13 Conference (ECT*, Trento), updated bibliography
Emergence of extreme events in a quasi-periodic oscillator
Creators: name: Durairaj, Premraj
name: Kanagaraj, Sathiyadevi
name: Kumarasamy, Suresh
name: Rajagopal, Karthikeyan
Publisher: name: arXiv
Year: 2023
Subjects: subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: FOS: Physical sciences

description: Extreme events are unusual and rare large-amplitude fluctuations that occur can unexpectedly in nonlinear dynamical systems. Events above the extreme event threshold of the probability distribution of a nonlinear process characterize extreme events. Different mechanisms for the generation of extreme events and their prediction measures have been reported in the literature. Based on the properties of extreme events, such as rare in frequency of occurrence and extreme in amplitude, various studies have shown that extreme events are both linear and nonlinear in nature. Interestingly, in this work, we report on a special class of extreme events which are nonchaotic and nonperiodic. These nonchaotic extreme events appear in between the quasi-periodic and chaotic dynamics of the system. We report the existence of such extreme events with various statistical measures and characterization techniques.
description: Accepted for Publication in Physical Review E Letter. 6 Pages, 6 Figures
„Illustrieren am Beispiel“ beim Beweisverstehen: Beispielkonstruktionsprozesse von Mathematikstudierenden
Creators: name: Bauer, Thomas
name: Müller-Hill, Eva
name: Neuhaus-Eckhardt, Silke
name: Rach, Stefanie
Publisher: name: Gesellschaft für Didaktik der Mathematik
Year: 2023
Subjects: subject: Beweisverstehen
subject: Illustrieren durch Beispiele
subject: Beispielkonstruktion
subject: Forschungssynthese
subject: Argumentieren
subject: Beweisen
subject: 510

description: Beweisverstehen ist für Studierende neben der Beweiskonstruktion eine der wesentlichen Anforderungssituationen im Bereich des Beweisens, etwa beim Nachvollziehen von Beweisen in Vorlesungen, Übungen oder Lehrbüchern. Jedoch zeigen viele Studierende Schwierigkeiten, Beweise zu verstehen(vgl. z.B. Selden, 2012; Weber, 2001). In der fachdidaktischen Forschung wird deshalb das Thema ‚Beweisverstehen‘ intensiv und facettenreich diskutiert (vgl. Sommerhoff & Brunner, 2021). Insbesondere werden unterschiedliche Unterstützungsstrategien für Verstehensprozesse der Studierenden untersucht, darunter das sogenannte ‚Illustrieren am Beispiel‘ (vgl. Mali, 2014; Mills, 2014), also die Illustration einzelner Beweiszeilen durch Beispiele. Dieser Beitrag stellt erste qualitative Erkenntnisse einer Mixed-Methods-Studie zu Möglichkeiten vor, Beweisverstehen durch Illustrieren am Beispiel in den Zusammenhang der bereits in Bauer et al. (2021) beschriebenen quantitativen Ergebnisse zu setzen und diskutiert mögliche Implikationen für das weitere Vorgehen.
Spectro-polarimetric view of bright atoll source GX 9+9 using IXPE and AstroSat
Creators: name: Chatterjee, Rwitika
name: Agrawal, Vivek K.
name: Jayasurya, Kiran M.
name: Katoch, Tilak
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We have carried out the first spectro-polarimetric study of the bright NS-LMXB GX 9+9 using IXPE and AstroSat observations. We report a significant detection of polarization of $1.7\pm 0.4\%$ over the $2-8$ keV energy band, with a polarization angle of $63^{\circ}\pm 7^{\circ}$. The polarization is found to be energy-dependent, with a $3σ$ polarization degree consistent with null polarization in $2-4$ keV, and $3.2\%$ in $4-8$ keV. Typical of the spectra seen in NS-LMXBs, we find that a combination of soft thermal emission from the accretion disc and Comptonized component from the optically thick corona produces a good fit to the spectra. We also attempt to infer the individual polarization of these components, and obtain a $3σ$ upper limit of $\sim 11\%$ on the polarization degree of the thermal component, and constrain that of the Comptonized component to $\sim 3\%$. We comment on the possible corona geometry of the system based on our results.
description: 5 pages, 6 figures, Accepted for publication in MNRAS Letters
Effective Matter Cosmologies of Massive Gravity I: Non-Physical Fluids
Creators: name: Yilmaz, Nejat Tevfik
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: For the massive gravity, after decoupling from the metric equation we find a broad class of solutions of the Stuckelberg sector by solving the background metric in the presence of a diagonal physical metric. We then construct the dynamics of the corresponding FLRW cosmologies which inherit effective matter contribution through the decoupling solution mechanism of the scalar sector.
description: 24 pages, minor revisions performed, published version
Anisotropic Quark Stars with an Interacting Quark Equation of State within the Complexity Factor Formalism
Creators: name: Rincon, Angel
name: Panotopoulos, Grigoris
name: Lopes, Ilidio
Publisher: name: arXiv
Year: 2023
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Within the framework of Einstein's General Relativity we study strange quark stars assuming an interacting equation-of-state. Taking into account the presence of anisotropies in a sphere made of ultra dense matter, we employ the formalism based on the complexity factor. We integrate the structure equations numerically imposing the appropriate conditions both at the center and at the surface of the stars, thus obtaining interior solutions describing hydrostatic equilibrium. Making use of well-established criteria, we demonstrate that the solutions obtained here are well behaved and realistic. A comparison with another, more conventional approach, is made as well. Our numerical results are summarized in a number of figures.
description: References updated
Ground-state cooling of a carbon nanomechanical resonator by spin-polarized current
Creators: name: Stadler, Pascal
name: Belzig, Wolfgang
name: Rastelli, Gianluca
Publisher: name: arXiv
Year: 2014
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We study the nonequilibrium steady state of a mechanical resonator in the quantum regime realized by a suspended carbon nanotube quantum dot contacted by two ferromagnets. Because of the spin-orbit interaction and/or an external magnetic field gradient, the spin on the dot couples directly to the flexural eigenmodes. Accordingly, the nanomechanical motion induces inelastic spin flips of the tunneling electrons. A spin-polarized current at finite bias voltage causes either heating or active cooling of the mechanical modes. We show that maximal cooling is achieved at resonant transport when the energy splitting between two dot levels of opposite spin equals the vibrational frequency. Even for weak electron-resonator coupling and moderate polarizations we can achieve ground-state cooling with a temperature of the leads, for instance, of $T=10ω$.
Criteria for Dynamical Timescale Mass Transfer of Metal-poor Intermediate-mass Stars
Creators: name: Ge, Hongwei
name: Tout, Christopher A.
name: Chen, Xuefei
name: Sarkar, Arnab
name: Walton, Dominic J.
name: Han, Zhanwen
Publisher: name: arXiv
Year: 2023
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The stability criteria of rapid mass transfer and common envelope evolution are fundamental in binary star evolution. They determine the mass, mass ratio and orbital distribution of many important systems, such as X-ray binaries, Type Ia supernovae and merging gravitational wave sources. We use our adiabatic mass-loss model to systematically survey the intermediate-mass stars' thresholds for dynamical-timescale mass transfer. The impact of metallicity on the stellar responses and critical mass ratios is explored. Both tables ($Z=0.001$) and fitting formula ($Z=0.001$ and $Z=0.02$) of critical mass ratios of intermediate-mass stars are provided. An application of our results to intermediate-mass X-ray binaries (IMXBs) is discussed. We find that the predicted upper limit to mass ratios, as a function of orbital period, is consistent with the observed IMXBs that undergo thermal or nuclear timescale mass transfer. According to the observed peak X-ray luminosity $L_\mathrm{X}$, we predict the range of $L_\mathrm{X}$ for IMXBs as a function of the donor mass and the mass transfer timescale.
description: 16 pages, 19 figures, 3 tables, accepted for publication in The Astrophysical Journal
Sparse Gröbner Bases: the Unmixed Case
Creators: name: Faugere, Jean-Charles
name: Spaenlehauer, Pierre-Jean
name: Svartz, Jules
Publisher: name: arXiv
Year: 2014
Subjects: subject: Symbolic Computation (cs.SC)
subject: FOS: Computer and information sciences

description: Toric (or sparse) elimination theory is a framework developped during the last decades to exploit monomial structures in systems of Laurent polynomials. Roughly speaking, this amounts to computing in a \emph{semigroup algebra}, \emph{i.e.} an algebra generated by a subset of Laurent monomials. In order to solve symbolically sparse systems, we introduce \emph{sparse Gröbner bases}, an analog of classical Gröbner bases for semigroup algebras, and we propose sparse variants of the $F_5$ and FGLM algorithms to compute them. Our prototype "proof-of-concept" implementation shows large speed-ups (more than 100 for some examples) compared to optimized (classical) Gröbner bases software. Moreover, in the case where the generating subset of monomials corresponds to the points with integer coordinates in a normal lattice polytope $\mathcal P\subset\mathbb R^n$ and under regularity assumptions, we prove complexity bounds which depend on the combinatorial properties of $\mathcal P$. These bounds yield new estimates on the complexity of solving $0$-dim systems where all polynomials share the same Newton polytope (\emph{unmixed case}). For instance, we generalize the bound $\min(n_1,n_2)+1$ on the maximal degree in a Gröbner basis of a $0$-dim. bilinear system with blocks of variables of sizes $(n_1,n_2)$ to the multilinear case: $\sum n_i - \max(n_i)+1$. We also propose a variant of Fröberg's conjecture which allows us to estimate the complexity of solving overdetermined sparse systems.
description: 20 pages, Corollary 6.1 has been corrected, ISSAC 2014, Kobe : Japan (2014)
Anderson tower of states and nematic order of spin-1 bosonic atoms on a 2D lattice
Creators: name: de Parny, L. de Forges
name: Yang, H-Y.
name: Mila, F.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: We investigate the structure of the spectrum of antiferromagnetically coupled spin-1 bosons on a square lattice using degenerate perturbation theory and exact diagonalizations of finite clusters. We show that the superfluid phase develops an Anderson tower of states typical of nematic long-range order with broken SU(2) symmetry.We further show that this order persists into the Mott insulating phase down to zero hopping for one boson per site, and down to a critical hopping for two bosons per site, in agreement with mean-field and Quantum Monte Carlo results. The connection with the transition between a fragmented condensate and a polar one in a single trap is briefly discussed.
description: 5 pages, 4 figures + 5 pages of supplemental material
A Dynamical Systems Approach to the Theory of Circumbinary Orbits in the Circular Restricted Problem
Creators: name: Langford, Andrew
name: Weiss, Lauren M.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Dynamical Systems (math.DS)
subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: To better understand the orbital dynamics of exoplanets around close binary stars, i.e., circumbinary planets (CBPs), we applied techniques from dynamical systems theory to a physically motivated set of solutions in the Circular Restricted Three-Body Problem (CR3BP). We applied Floquet theory to characterize the linear dynamical behavior -- static, oscillatory, or exponential -- surrounding planar circumbinary periodic trajectories (limit cycles). We computed prograde and retrograde limit cycles and analyzed their geometries, stability bifurcations, and dynamical structures. Orbit and stability calculations are exact computations in the CR3BP and reproducible through the open-source Python package pyraa. The periodic trajectories produce a set of non-crossing, dynamically cool circumbinary orbits conducive to planetesimal growth. For mass ratios $μ\in [0.01, 0.50]$ we found recurring features in the prograde families. These features include: (1) an innermost near-circular trajectory, inside which solutions have resonant geometries, (2) an innermost stable trajectory ($a_{cr} \approx 1.61 - 1.85 \, a_\textrm{bin}$) characterized by a tangent bifurcating limit cycle, and (3) a region of dynamical instability ($a \approx 2.1 \ a_\textrm{bin}; Δa \approx 0.1 \ a_\textrm{bin}$), the exclusion zone, bounded by a pair of critically stable trajectories -- bifurcating limit cycles. The exterior boundary of the exclusion zone is consistent with prior determinations of $a_{cr}$ around a circular binary. We validate our analytic results with N-body simulations and apply them to the Pluto-Charon system. The absence of detected CBPs in the inner stable region, between the prograde exclusion zone and $a_{cr}$, suggests that the exclusion zone may inhibit the inward migration of CBPs.
description: Accepted for publication in The Astronomical Journal. 31 pages, 17 figures, 4 tables, open-source results from numerical computations
High-Order Fully General-Relativistic Hydrodynamics: new Approaches and Tests
Creators: name: Radice, David
name: Rezzolla, Luciano
name: Galeazzi, Filippo
Publisher: name: arXiv
Year: 2013
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We present a new approach for achieving high-order convergence in fully general-relativistic hydrodynamic simulations. The approach is implemented in WhiskyTHC, a new code that makes use of state-of-the-art numerical schemes and was key in achieving, for the first time, higher than second-order convergence in the calculation of the gravitational radiation from inspiraling binary neutron stars Radice et al. (2013). Here, we give a detailed description of the algorithms employed and present results obtained for a series of classical tests involving isolated neutron stars. In addition, using the gravitational-wave emission from the late inspiral and merger of binary neutron stars, we make a detailed comparison between the results obtained with the new code and those obtained when using standard second-order schemes commonly employed for matter simulations in numerical relativity. We find that even at moderate resolutions and for binaries with large compactness, the phase accuracy is improved by a factor 50 or more.
description: 34 pages, 16 figures. Version accepted on CQG
Monogamy and backflow of mutual information in non-Markovian thermal baths
Creators: name: Costa, A. C. S.
name: Angelo, R. M.
name: Beims, M. W.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We investigate the dynamics of information among the parties of tripartite systems. We start by proving two results concerning the monogamy of mutual information. The first one states that mutual information is monogamous for generic tripartite pure states. The second shows that in general mutual information is monogamous only if the amount of genuine tripartite correlations is large enough. Then, we analyze the internal dynamics of tripartite systems whose parties do not exchange energy. In particular, we allow for one of the subsystems to play the role of a finite thermal bath. As a result, we find a typical scenario in which local information tends to be converted into delocalized information. Moreover, we show that (i) the information flow is reversible for finite thermal baths at low temperatures, (ii) monogamy of mutual information is respected throughout the dynamics, and (iii) genuine tripartite correlations are typically present. Finally, we analytically calculate a quantity capable of revealing favorable regimes for non-Markovianity in our model.
description: 9 pages, 4 figures
An Earth-sized Planet around an M5 Dwarf Star at 22 pc
Creators: name: Hirano, Teruyuki
name: Dai, Fei
name: Livingston, John H.
name: Kasagi, Yui
name: Narita, Norio
name: Ishikawa, Hiroyuki Tako
name: Grziwa, Sascha
name: Lam, Kristine W. F.
name: Miyakawa, Kohei
name: Serrano, Luisa M.
name: Matsumoto, Yuji
name: Kokubo, Eiichiro
name: Kimura, Tadahiro
name: Ikoma, Masahiro
name: Winn, Joshua N.
name: Wisniewski, John P.
name: Harakawa, Hiroki
name: Teng, Huan-Yu
name: Cochran, William D.
name: Fukui, Akihiko
name: Gandolfi, Davide
name: Guenther, Eike W.
name: Hori, Yasunori
name: Ikuta, Kai
name: Kawauchi, Kiyoe
name: Knudstrup, Emil
name: Korth, Judith
name: Kotani, Takayuki
name: Krishnamurthy, Vigneshwaran
name: Kudo, Tomoyuki
name: Kurokawa, Takashi
name: Kuzuhara, Masayuki
name: Luque, Rafael
name: Mori, Mayuko
name: Nishikawa, Jun
name: Omiya, Masashi
name: Orell-Miquel, Jaume
name: Palle, Enric
name: Persson, Carina M.
name: Redfield, Seth
name: Serabyn, Eugene
name: Smith, Alexis M. S.
name: Takahashi, Aoi
name: Takarada, Takuya
name: Ueda, Akitoshi
name: Van Eylen, Vincent
name: Vievard, Sebastien
name: Tamura, Motohide
name: Sato, Bun'ei
Publisher: name: arXiv
Year: 2023
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We report on the discovery of an Earth-sized transiting planet ($R_p=1.015\pm0.051\,R_\oplus$) in a $P=4.02$ day orbit around K2-415 (EPIC 211414619), an M5V star at 22 pc. The planet candidate was first identified by analyzing the light curve data by the K2 mission, and is here shown to exist in the most recent data from TESS. Combining the light curves with the data secured by our follow-up observations including high-resolution imaging and near infrared spectroscopy with IRD, we rule out false positive scenarios, finding a low false positive probability of $2\times 10^{-4}$. Based on IRD's radial velocities of K2-415, which were sparsely taken over three years, we obtain the planet mass of $3.0\pm 2.7\,M_\oplus$ ($M_p<7.5\,M_\oplus$ at $95\,\%$ confidence) for K2-415b. Being one of the lowest mass stars ($\approx 0.16\,M_\odot$) known to host an Earth-sized transiting planet, K2-415 will be an interesting target for further follow-up observations, including additional radial velocity monitoring and transit spectroscopy.
description: 20 pages, 12 figures, accepted for publication in AJ
The classical nonlinear Schrödinger model with a new integrable boundary
Creators: name: Zambon, Cristina
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: A new integrable boundary for the classical nonlinear Schrödinger model is derived by dressing a boundary with a defect. A complete investigation of the integrability of the new boundary is carried out in the sense that the boundary ${\cal K}$ matrix is derived and the integrability is proved via the classical $r$-matrix. The issue of conserved charges is also discussed. The key point in proving the integrability of the new boundary is the use of suitable modified Poisson brackets. Finally, concerning the kind of defect used in the present context, this investigation offers the opportunity to prove - beyond any doubts - their integrability.
description: 16 pages. Additional information added in section 4.1
TESS Asteroseismic Analysis of HD 76920: The Giant Star Hosting An Extremely Eccentric Exoplanet
Creators: name: Jiang, Chen
name: Wu, Tao
name: Feinstein, Adina D.
name: Stassun, Keivan G.
name: Bedding, Timothy R.
name: Veras, Dimitri
name: Corsaro, Enrico
name: Buzasi, Derek L.
name: Stello, Dennis
name: Li, Yaguang
name: Mathur, Savita
name: Garcia, Rafael A.
name: Breton, Sylvain N.
name: Lundkvist, Mia S.
name: Mikolajczyk, Przemyslaw J.
name: Gehan, Charlotte
name: Campante, Tiago L.
name: Bossini, Diego
name: Kane, Stephen R.
name: Ong, Jia Mian Joel
name: Yildiz, Mutlu
name: Kayhan, Cenk
name: Orhan, Zeynep Celik
name: Ortel, Sibel
name: Zhang, Xinyi
name: Cunha, Margarida S.
name: de Moura, Bruno Lustosa
name: Yu, Jie
name: Huber, Daniel
name: Ou, Jian-wen
name: Wittenmyer, Robert A.
name: Gizon, Laurent
name: Chaplin, William J.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: The Transiting Exoplanet Survey Satellite (TESS) mission searches for new exoplanets. The observing strategy of TESS results in high-precision photometry of millions of stars across the sky, allowing for detailed asteroseismic studies of individual systems. In this work, we present a detailed asteroseismic analysis of the giant star HD 76920 hosting a highly eccentric giant planet ($e = 0.878$) with an orbital period of 415 days, using 5 sectors of TESS light curve that cover around 140 days of data. Solar-like oscillations in HD 76920 are detected around $52 \, μ$Hz by TESS for the first time. By utilizing asteroseismic modeling that takes classical observational parameters and stellar oscillation frequencies as constraints, we determine improved measurements of the stellar mass ($1.22 \pm 0.11\, M_\odot$), radius ($8.68 \pm 0.34\,R_\odot$), and age ($5.2 \pm 1.4\,$Gyr). With the updated parameters of the host star, we update the semi-major axis and mass of the planet as $a=1.165 \pm 0.035$ au and $M_{\rm p}\sin{i} = 3.57 \pm 0.22\,M_{\rm Jup}$. With an orbital pericenter of $0.142 \pm 0.005$ au, we confirm that the planet is currently far away enough from the star to experience negligible tidal decay until being engulfed in the stellar envelope. We also confirm that this event will occur within about 100\,Myr, depending on the stellar model used.
description: 18 pages, 7 figures, 4 tables
Boundary Non-Crossings of Additive Wiener Fields
Creators: name: Hashorva, Enkelejd
name: Mishura, Yuliya
Publisher: name: arXiv
Year: 2014
Subjects: subject: Probability (math.PR)
subject: Statistics Theory (math.ST)
subject: FOS: Mathematics

description: Let $W_i=\{W_i(t), t\in \mathbb{R}_+\}, i=1,2$ be two Wiener processes and $W_3=\{W_3(\mathbf{t}), \mathbf{t}\in \mathbb{R}_+^2\}$ be a two-parameter Brownian sheet, all three processes being mutually independent. We derive upper and lower bounds for the boundary non-crossing probability $$P_f=P\{W_1(t_1)+W_2(t_2)+W_3(\mathbf{t})+h(\mathbf{t})\leq u(\mathbf{t}), \mathbf{t}\in\mathbb{R}_+^2\},$$ where $h, u: \mathbb{R}_+^2\rightarrow \mathbb{R}_+$ are two measurable functions. We show further that for large trend functions $γf>0$ asymptotically when $γ\to \infty$ we have that $\ln P_{γf}$ is the same as $\ln P_{γ\underline{f}}$ where $\underline{f}$ is the projection of $f$ on some closed convex set of the reproducing kernel Hilbert Space of $W$. It turns out that our approach is applicable also for the additive Brownian pillow.
description: 14 pages
Strange and charm quark contributions to the anomalous magnetic moment of the muon
Creators: name: Chakraborty, Bipasha
name: Davies, C. T. H.
name: Donald, G. C.
name: Dowdall, R. J.
name: Koponen, J.
name: Lepage, G. P.
name: Teubner, T.
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We describe a new technique to determine the contribution to the anomalous magnetic moment of the muon coming from the hadronic vacuum polarization using lattice QCD. Our method reconstructs the Adler function, using Padé approximants, from its derivatives at $q^2=0$ obtained simply and accurately from time-moments of the vector current-current correlator at zero spatial momentum. We test the method using strange quark correlators on large-volume gluon field configurations that include the effect of up and down (at physical masses), strange and charm quarks in the sea at multiple values of the lattice spacing and multiple volumes and show that 1% accuracy is achievable. For the charm quark contributions we use our previously determined moments with up, down and strange quarks in the sea on very fine lattices. We find the (connected) contribution to the anomalous moment from the strange quark vacuum polarization to be $a_μ^s = 53.41(59) \times 10^{-10}$, and from charm to be $a_μ^c = 14.42(39)\times 10^{-10}$. These are in good agreement with flavour-separated results from non-lattice methods, given caveats about the comparison. The extension of our method to the light quark contribution and to that from the quark-line disconnected diagram is straightforward.
description: 7 pages, 4 figures. Updated to version accepted for publication, with additional clarification of the new method developed here
Studies of the equation-of-state of nuclear matter by heavy-ion collisions at intermediate energy in the multi-messenger era
Creators: name: Russotto, P.
name: Cozma, M. D.
name: De Filippo, E.
name: Fèvre, A. Le
name: Leifels, Y.
name: Łukasik, J.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The study of the equation-of-state (EoS) describing the properties of nuclear matter away from the normal conditions is a relevant and intriguing topic of modern nuclear physics. The last decades have witnessed a substantial experimental progress in derivation of the symmetric matter term of the EoS and of the so-called symmetry energy for the asymmetric matter, especially at densities below the saturation point. But it is only in recent years that the opening of the multi-messenger astronomy era, triggered by detection of gravitational waves due to the neutron star mergers, has renewed and enlarged the interest in high-density EoS, being the main ingredient for determining the structure and properties of neutron stars. In this paper we review our knowledge obtained from heavy-ion collisions up to the 1 GeV/nucleon regime, on the EoS above nuclear saturation density. Special emphasis is given on the still few results on symmetry energy at high densities and their interconnections with multi-messenger astronomy findings.
description: 79 pages, 25 figures
Cogenesis in a universe with vanishing $B-L$ within a gauged $U(1)_x$ extension
Creators: name: Feng, Wan-Zhe
name: Nath, Pran
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We consider a gauged $U(1)_x$ extension of the standard model and of the minimal supersymmetric standard model where the dark matter fields are charged under $U(1)_x$ and carry lepton number while the standard model fields and fields of the minimal supersymmetric standard model are neutral under $U(1)_x$. We consider leptogenesis in this class of models with all fundamental interactions having no violation of lepton number, and the total $B-L$ in the universe vanishes. Such leptogenesis leads to equal and opposite lepton numbers in the visible sector and in the dark sector, and thus also produces asymmetric dark matter. Part of the lepton numbers generated in the leptonic sector subsequently transfer to the baryonic sector via sphaleron interactions. The stability of the dark particles is protected by the $U(1)_x$ gauge symmetry. A kinetic mixing between the $U(1)_x$ and the $U(1)_Y$ gauge bosons allows for dissipation of the symmetric component of dark matter. The case when $U(1)_x$ is $U(1)_{B-L}$ is also discussed for the supersymmetric case. This case is particularly interesting in that we have a gauged $U(1)_{B-L}$ which ensures the conservation of $B-L$ with an initial condition of a vanishing $B-L$ in the universe. Phenomenological implications of the proposed extensions are discussed, which include implications for electroweak physics, neutrino masses and mixings, and lepton flavor changing processes such as $\ell_i \to \ell_j γ$. We also briefly discuss the direct detection of the dark matter in the model.
description: 9 pages, 3 figures
Tuning the Interlayer Microstructure and Residual Stress of Buffer-Free Direct Bonding GaN/Si Heterostructures
Creators: name: Zhou, Yan
name: Zhou, Shi
name: Wan, Shun
name: Zou, Bo
name: Feng, Yuxia
name: Mei, Rui
name: Wu, Heng
name: Tan, Pingheng
name: Shigekawa, Naoteru
name: Liang, Jianbo
name: Kuball, Martin
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: The direct integration of GaN with Si can boost great potential for low-cost, large-scale, and high-power device applications. However, it is still challengeable to directly grow GaN on Si without using thick strain relief buffer layers due to their large lattice and thermal-expansion-coefficient mismatches. In this work, a GaN/Si heterointerface without any buffer layer is successfully fabricated at room temperature via surface activated bonding (SAB). The residual stress states and interfacial microstructures of GaN/Si heterostructures were systematically investigated through micro-Raman spectroscopy and transmission electron microscopy. Compared to the large compressive stress that existed in GaN layers grown-on-Si by MOCVD, a significantly relaxed and uniform small tensile stress was observed in GaN layers bonded-to-Si by SAB; this is mainly ascribed to the amorphous layer formed at the bonding interface. In addition, the interfacial microstructure and stress states of bonded GaN/Si heterointerfaces was found can be significantly tuned by appropriate thermal annealing. This work moves an important step forward directly integrating GaN to the present Si CMOS technology with high quality thin interfaces, and brings great promises for wafer-scale low-cost fabrication of GaN electronics.
description: 15 pages, 3 figures
Fermi-LAT Gamma-ray Emission Discovered from the Composite Supernova Remnant B0453-685 in the Large Magellanic Cloud
Creators: name: Eagle, Jordan
name: Castro, Daniel
name: Mahhov, Peter
name: Gelfand, Joseph
name: Kerr, Matthew
name: Slane, Patrick
name: Ballet, Jean
name: Acero, Fabio
name: Straal, Samayra
name: Ajello, Marco
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We report the second extragalactic pulsar wind nebula (PWN) to be detected in the MeV-GeV band by the Fermi-LAT, located within the Large Magellanic Cloud (LMC). The only other known PWN to emit in the Fermi band outside of the Milky Way Galaxy is N 157B which lies to the west of the newly detected gamma-ray emission at an angular distance of 4 degrees. Faint, point-like gamma-ray emission is discovered at the location of the composite supernova remnant (SNR) B0453-685 with a ~ 4 sigma significance from energies 300 MeV - 2 TeV. We present the Fermi-LAT data analysis of the new gamma-ray source, coupled with a detailed multi-wavelength investigation to understand the nature of the observed emission. Combining the observed characteristics of the SNR and the physical implications from broadband modeling, we argue it is unlikely the SNR is responsible for the gamma-ray emission. While the gamma-ray emission is too faint for a pulsation search, we try to distinguish between any pulsar and PWN component of SNR B0453-685 that would be responsible for the observed gamma-ray emission using semi-analytic models. We determine the most likely scenario is that the old PWN (t ~ 14,000 years) within B0453-685 has been impacted by the return of the SNR reverse shock with a possible substantial pulsar component below 5 GeV.
description: 18 pages, 8 figures, accepted for publication in ApJ Feb. 1, 2023
Theory of magnetotransport in shaped topological insulator nanowires
Creators: name: Graf, Ansgar
name: Kozlovsky, Raphael
name: Richter, Klaus
name: Gorini, Cosimo
Publisher: name: Universität Regensburg
Year: 2020
Subjects: subject: 530 Physik

description: We show that shaped topological insulator (TI) nanowires, i.e. such that their cross-section radius varies along the wire length, can be tuned into a number of different transport regimes when immersed in a homogeneous coaxial magnetic field. This is in contrast with widely studied tubular nanowires with constant cross-section, and is due to magnetic confinement of Dirac surface carriers. In flat 2D systems such a confinement requires non-homogeneous magnetic fields, while for shaped nanowires of standard size homogeneous fields of the order of B∼1T are sufficient. We put recent work [Kozlovsky et al., Phys. Rev. Lett. 124, 126804 (2020)] into broader context and extend it to deal with axially symmetric wire geometries with arbitrary radial profile. A dumbbell-shaped TI nanowire is used as a paradigmatic example for transport through a constriction and shown to be tunable into five different transport regimes: (i) conductance steps, (ii) resonant transmission, (iii) current suppression, (iv) Coulomb blockade, and (v) transport through a triple quantum dot. Switching between regimes is achieved by modulating the strength of a coaxial magnetic field and does not require strict axial symmetry of the wire cross-section. As such, it should be observable in TI nanowires fabricated with available experimental techniques.