cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Anisotropic Hanle lineshape via anisotropic magnetothermoelectric phenomena
Creators: name: Das, K. S.
name: Dejene, F. K.
name: van Wees, B. J.
name: Vera-Marun, I. J.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We observe anisotropic Hanle lineshape with unequal in-plane and out-of-plane non-local signals for spin precession measurements carried out on lateral metallic spin valves with transparent interfaces. The conventional interpretation for this anisotropy corresponds to unequal spin relaxation times for in-plane and out-of-plane spin orientations as for the case of 2D materials like graphene, but it is unexpected in a polycrystalline metallic channel. Systematic measurements as a function of temperature and channel length, combined with both analytical and numerical thermoelectric transport models, demonstrate that the anisotropy in the Hanle lineshape is magneto-thermal in origin, caused by the anisotropic modulation of the Peltier and Seebeck coefficients of the ferromagnetic electrodes. Our results call for the consideration of such magnetothermoelectric effects in the study of anisotropic spin relaxation.
Teachers' response to school based curriculum development in Victorian government schools
Creators: name: Kee, Kevin Norman
Publisher: name: Monash University
Year: 2021

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
Ultra-high-linearity integrated lithium niobate electro-optic modulators
Creators: name: Feng, Hanke
name: Zhang, Ke
name: Sun, Wenzhao
name: Ren, Yangming
name: Zhang, Yiwen
name: Zhang, Wenfu
name: Wang, Cheng
Publisher: name: arXiv
Year: 2022
Subjects: subject: Optics (physics.optics)
subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: Integrated lithium niobate (LN) photonics is a promising platform for future chip-scale microwave photonics systems owing to its unique electro-optic properties, low optical loss and excellent scalability. A key enabler for such systems is a highly linear electro-optic modulator that could faithfully covert analog electrical signals into optical signals. In this work, we demonstrate a monolithic integrated LN modulator with an ultrahigh spurious-free dynamic range (SFDR) of 120.04 dB Hz4/5 at 1 GHz, using a ring-assisted Mach-Zehnder interferometer configuration. The excellent synergy between the intrinsically linear electro-optic response of LN and an optimized linearization strategy allows us to fully suppress the cubic terms of third-order intermodulation distortions (IMD3) without active feedback controls, leading to ~ 20 dB improvement over previous results in the thin-film LN platform. Our ultra-high-linearity LN modulators could become a core building block for future large-scale functional microwave photonic integrated circuits, by further integration with other high-performance components like low-loss delay lines, tunable filters and phase shifters available on the LN platform.
Particle-hole spectral asymmetry at the edge of multiorbital noncentrosymmetric superconductors
Creators: name: Fukaya, Yuri
name: Yada, Keiji
name: Tanaka, Yukio
name: Gentile, Paola
name: Cuoco, Mario
Publisher: name: arXiv
Year: 2022
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Bogoliubov quasiparticles are a coherent electron-hole quantum superposition which typically, for time-reversal symmetric superconductors, exhibit a spectral distribution with particle-hole symmetry. Here, we demonstrate that in two-dimensional noncentrosymmetric superconductors with multiorbital spin-triplet pairing the energy profile of the density of states at the edge can violate this paradigm. We show that the structure of Andreev reflections generally leads to pairing states made of configurations that are orbitally split due to the low degree of crystalline symmetry at the edge. The resulting pairing state has a mixed parity character in the orbital sector that, in the presence of reduced crystal symmetry at the edge, sets out a particle-hole asymmetric profile for the spectral function. These findings indicate a path to design asymmetric spectral functions at the edge of superconductors with orbital degrees of freedom and time-reversal symmetry. The emerging signatures can be exploited for the detection of spin-triplet pairing equipped with internal degrees of freedom.
description: 9 pages, 4 figures, and 10 pages, 7 figures in supplemental materials
A noise-induced transition in the Lorenz system
Creators: name: Zelati, Michele Coti
name: Hairer, Martin
Publisher: name: arXiv
Year: 2020
Subjects: subject: Probability (math.PR)
subject: Classical Analysis and ODEs (math.CA)
subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics
subject: 60H10, 37H20

description: We consider a stochastic perturbation of the classical Lorenz system in the range of parameters for which the origin is the global attractor. We show that adding noise in the last component causes a transition from a unique to exactly two ergodic invariant measures. The bifurcation threshold depends on the strength of the noise: if the noise is weak, the only invariant measure is Gaussian, while strong enough noise causes the appearance of a second ergodic invariant measure.
description: Final draft; some typos fixed compared to the published version
On the quantum spin glass transition on the Bethe lattice
Creators: name: Mossi, Gianni
name: Parolini, Tommaso
name: Pilati, Sebastiano
name: Scardicchio, Antonello
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: We investigate the ground-state properties of a disorderd Ising model with uniform transverse field on the Bethe lattice, focusing on the quantum phase transition from a paramagnetic to a glassy phase that is induced by reducing the intensity of the transverse field. We use a combination of quantum Monte Carlo algorithms and exact diagonalization to compute Rényi entropies, quantum Fisher information, correlation functions and order parameter. We locate the transition by means of the peak of the Rényi entropy and we find agreement with the transition point estimated from the emergence of finite values of the Edwards-Anderson order parameter and from the peak of the correlation length. We interpret the results by means of a mean-field theory in which quantum fluctuations are treated as massive particles hopping on the interaction graph. We see that the particles are delocalized at the transition, a fact that points towards the existence of possibly another transition deep in the glassy phase where these particles localize, therefore leading to a many-body localized phase.
description: 18 pages, 17 figures
Extreme star formation events in quasar hosts over ${\bf0.5
Creators: name: Pitchford, Lura K.
name: Hatziminaoglou, Evanthia
name: Feltre, Anna
name: Farrah, Duncan
name: Clarke, Charlotte
name: Harris, Kathryn
name: Hurley, Peter
name: Oliver, Sebastian
name: Page, Mathew
name: Wang, Lingyu
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We explore the relationship between active galactic nuclei and star formation in a sample of 513 optically luminous type 1 quasars up to redshifts of $\sim$4 hosting extremely high star formation rates (SFRs). The quasars are selected to be individually detected by the \textit{Herschel} SPIRE instrument at $> $3$σ$ at 250 $μ$m, leading to typical SFRs of order of 1000 M$_{\odot}$yr$^{-1}$. We find the average SFRs to increase by almost a factor 10 from $z\sim0.5$ to $z\sim3$, mirroring the rise in the comoving SFR density over the same epoch. However, we find that the SFRs remain approximately constant with increasing accretion luminosity for accretion luminosities above 10$^{12}$ L$_{\odot}$. We also find that the SFRs do not correlate with black hole mass. Both of these results are most plausibly explained by the existence of a self-regulation process by the starburst at high SFRs, which controls SFRs on time-scales comparable to or shorter than the AGN or starburst duty cycles. We additionally find that SFRs do not depend on Eddington ratio at any redshift, consistent with no relation between SFR and black hole growth rate per unit black hole mass. Finally, we find that high-ionisation broad absorption line (HiBAL) quasars have indistinguishable far-infrared properties to those of classical quasars, consistent with HiBAL quasars being normal quasars observed along a particular line of sight, with the outflows in HiBAL quasars not having any measurable effect on the star formation in their hosts.
description: 12 pages, 6 figures
Supporting collaborative critiquing in an online environment for novice video designers
Creators: name: Teo, Yiong Hwee
Publisher: name: Monash University
Year: 2021

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
Carbon Decorated TiO2 Nanotube Membranes: A Renewable Nanofilter for Size- and Charge Selective Enrichment of Proteins
Creators: name: Xu, Jingwen
name: Yang, Lingling
name: Han, Yuyao
name: Wang, Yongmei
name: Zhou, Xuemei
name: Gao, Zhida
name: Song, Yan-Yan
name: Schmuki, Patrik
Publisher: name: arXiv
Year: 2016
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: In this work, we design a TiO2 nanomembrane (TiNM) that can be used as a nanofilter platform for a selective enrichment of specific proteins. After use the photocatalytic properties of TiO2 allow to decompose unwanted remnant on the substrate and thus make the platform reusable. To construct this platform we fabricate a free-standing TiO2 nanotube array and remove the bottom oxide to form a both-end open TiNM. By pyrolysis of the natural tube wall contamination (C/TiNM), the walls become decorated with graphitic carbon patches. Owing to the large surface area, the amphiphilic nature and the charge adjustable character, this C/TiNM can be used to extract and enrich hydrophobic and charged biomolecules from solutions. Using human serum albumin (HSA) as a model protein as well as protein mixtures, we show that the composite membrane exhibits a highly enhanced loading capacity and protein selectivity and is reusable after a short UV treatment.
High-order Methods for a Pressure Poisson Equation Reformulation of the Navier-Stokes Equations with Electric Boundary Conditions
Creators: name: Rosales, Rodolfo Ruben
name: Seibold, Benjamin
name: Shirokoff, David
name: Zhou, Dong
Publisher: name: arXiv
Year: 2020
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics
subject: 65L06, 65M60, 76D05

description: Pressure Poisson equation (PPE) reformulations of the incompressible Navier-Stokes equations (NSE) replace the incompressibility constraint by a Poisson equation for the pressure and a suitable choice of boundary conditions. This yields a time-evolution equation for the velocity field only, with the pressure gradient acting as a nonlocal operator. Thus, numerical methods based on PPE reformulations, in principle, have no limitations in achieving high order. In this paper, it is studied to what extent high-order methods for the NSE can be obtained from a specific PPE reformulation with electric boundary conditions (EBC). To that end, implicit-explicit (IMEX) time-stepping is used to decouple the pressure solve from the velocity update, while avoiding a parabolic time-step restriction; and mixed finite elements are used in space, to capture the structure imposed by the EBC. Via numerical examples, it is demonstrated that the methodology can yield at least third order accuracy in space and time.
The Kelvin-Helmholtz instability at the boundary of relativistic magnetized jets
Creators: name: Chow, Anthony
name: Davelaar, Jordy
name: Rowan, Michael
name: Sironi, Lorenzo
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We study the linear stability of a planar interface separating two fluids in relative motion, focusing on conditions appropriate for the boundaries of relativistic jets. The jet is magnetically dominated, whereas the ambient wind is gas-pressure dominated. We derive the most general form of the dispersion relation and provide an analytical approximation of its solution for an ambient sound speed much smaller than the jet Alfvén speed $v_A$, as appropriate for realistic systems. The stability properties are chiefly determined by the angle $ψ$ between the wavevector and the jet magnetic field. For $ψ=π/2$, magnetic tension plays no role, and our solution resembles the one of a gas-pressure dominated jet. Here, only sub-Alfvénic jets are unstable ($0
description: 9 pages, 6 figures, submitted to journal
Measurements of Rayleigh Ratios in Linear Alkylbenzene
Creators: name: Yu, Miao
name: Wu, Wenjie
name: Peng, Na
name: Yu, Taozhe
name: Ding, Yayun
name: Liu, Qian
name: Ren, Feng
name: Zhang, Zhenyu
name: Zhou, Xiang
Publisher: name: arXiv
Year: 2022
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: In present work an experiment has been designed to measure the Rayleigh ratio directly at $405$ nm and $432$ nm for linear alkylbenzene which is a common solvent used in liquid scintillator detectors of neutrino experiments. The perpendicularly polarized Rayleigh ratio is determined to be $(4.52\pm 0.28)\times 10^{-6}$ m$^{-1}\cdot$ sr$^{-1}$ at $405$ nm and $(3.82\pm 0.24)\times 10^{-6}$ m$^{-1}\cdot$ sr$^{-1}$ at $432$ nm, and the corresponding Rayleigh scattering length is $L_{Ray} = 22.9\pm 0.3(\mathrm{stat.})\pm 1.7(\mathrm{sys.})$ m at $405$ nm and $L_{Ray}= 27.0\pm 0.9(\mathrm{stat.})\pm 1.8(\mathrm{sys.})$ m at $432$ nm.
description: 16 pages, 7 figures
Transcriptional and Post-Transcriptional Regulation and Transcriptional Memory of Chromatin Regulators in Response to Low Temperature
Creators: name: Vyse, Kora
name: Faivre, Léa
name: Romich, Melissa
name: Pagter, Majken
name: Schubert, Daniel
name: Hincha, Dirk K.
name: Zuther, Ellen
Publisher: name: Freie Universität Berlin
Year: 2020
Subjects: subject: chromatin regulators
subject: quantitative reverse transcription polymerase chain reaction platform
subject: histones
subject: cold acclimation
subject: deacclimation
subject: 500 Naturwissenschaften und Mathematik::580 Pflanzen (Botanik)::580 Pflanzen (Botanik)

description: Chromatin regulation ensures stable repression of stress-inducible genes under non-stress conditions and transcriptional activation and memory of stress-related genes after stress exposure. However, there is only limited knowledge on how chromatin genes are regulated at the transcriptional and post-transcriptional level upon stress exposure and relief from stress. We reveal that the repressive modification histone H3 lysine 27 trimethylation (H3K27me3) targets genes which are quickly activated upon cold exposure, however, H3K27me3 is not necessarily lost during a longer time in the cold. In addition, we have set-up a quantitative reverse transcription polymerase chain reaction-based platform for high-throughput transcriptional profiling of a large set of chromatin genes. We find that the expression of many of these genes is regulated by cold. In addition, we reveal an induction of several DNA and histone demethylase genes and certain histone variants after plants have been shifted back to ambient temperature (deacclimation), suggesting a role in the memory of cold acclimation. We also re-analyze large scale transcriptomic datasets for transcriptional regulation and alternative splicing (AS) of chromatin genes, uncovering an unexpected level of regulation of these genes, particularly at the splicing level. This includes several vernalization regulating genes whose AS may result in cold-regulated protein diversity. Overall, we provide a profiling platform for the analysis of chromatin regulatory genes and integrative analyses of their regulation, suggesting a dynamic regulation of key chromatin genes in response to low temperature stress.
Negative refraction in hyperbolic hetero-bicrystals
Creators: name: Sternbach, A. J.
name: Moore, S. L.
name: Rikhter, A.
name: Zhang, S.
name: Jing, R.
name: Shao, Y.
name: Kim, B. S. Y.
name: Xu, S.
name: Liu, S.
name: Edgar, J. H.
name: Rubio, A.
name: Dean, C.
name: Hone, J.
name: Fogler, M. M.
name: Basov, D. N.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We visualized negative refraction of phonon polaritons, which occurs at the interface between two natural crystals. The polaritons - hybrids of infrared photons and lattice vibrations - form collimated rays that display negative refraction when passing through a planar interface between the two hyperbolic van der Waals materials: molybdenum oxide ($MoO_3$) and isotopically pure hexagonal boron nitride ($h^{11}BN$). At a special frequency $ω_0$, these rays can circulate along closed diamond-shaped trajectories. We have shown that polariton eigenmodes display regions of both positive and negative dispersion interrupted by multiple gaps that result from polaritonic level repulsion and strong coupling.
Parents and pupil control ideology : some aspects of the home-school relationship.
Creators: name: McGregor, Robert
Publisher: name: Monash University
Year: 2021

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
Testing by Dualization
Creators: name: Li, Yishuai
Publisher: name: arXiv
Year: 2022
Subjects: subject: Programming Languages (cs.PL)
subject: Software Engineering (cs.SE)
subject: FOS: Computer and information sciences

description: Software engineering requires rigorous testing to guarantee the product's quality. Semantic testing of functional correctness is challenged by nondeterminism in behavior, which makes testers difficult to write and reason about. This thesis presents a language-based technique for testing interactive systems. I propose a theory for specifying and validating nondeterministic behaviors, with guaranteed soundness and correctness. I then apply the theory to testing practices, and show how to derive specifications into interactive tester programs. I also introduce a language design for producing test inputs that can effectively detect and reproduce invalid behaviors. I evaluate the methodology by specifying and testing real-world systems such as web servers and file synchronizers, demonstrating the derived testers' ability to find disagreements between the specification and the implementation.
On the geometry of the symmetrized bidisc
Creators: name: Bhattacharyya, Tirthankar
name: Biswas, Anindya
name: Maitra, Anwoy
Publisher: name: arXiv
Year: 2020
Subjects: subject: Complex Variables (math.CV)
subject: FOS: Mathematics

description: We study the action of the automorphism group of the $2$ complex dimensional manifold symmetrized bidisc $\mathbb{G}$ on itself. The automorphism group is 3 real dimensional. It foliates $\mathbb{G}$ into leaves all of which are 3 real dimensional hypersurfaces except one, viz., the royal variety. This leads us to investigate Isaev's classification of all Kobayashi-hyperbolic 2 complex dimensional manifolds for which the group of holomorphic automorphisms has real dimension 3 studied by Isaev. Indeed, we produce a biholomorphism between the symmetrized bidisc and the domain \[\{(z_1,z_2)\in \mathbb{C} ^2 : 1+|z_1|^2-|z_2|^2>|1+ z_1 ^2 -z_2 ^2|, Im(z_1 (1+\overline{z_2}))>0\}\] in Isaev's list. Isaev calls it $\mathcal D_1$. The road to the biholomorphism is paved with various geometric insights about $\mathbb{G}$. Several consequences of the biholomorphism follow including two new characterizations of the symmetrized bidisc and several new characterizations of $\mathcal D_1$. Among the results on $\mathcal D_1$, of particular interest is the fact that $\mathcal D_1$ is a "symmetrization". When we symmetrize (appropriately defined in the context in the last section) either $Ω_1$ or $\mathcal{D}^{(2)}_1$ (Isaev's notation), we get $\mathcal D_1$. These two domains $Ω_1$ and $\mathcal{D}^{(2)}_1$ are in Isaev's list and he mentioned that these are biholomorphic to $\mathbb{D} \times \mathbb{D}$. We produce explicit biholomorphisms between these domains and $\mathbb{D} \times \mathbb{D}$.
description: 22 pages, Accepted in Indiana University Mathematics Journal
Conservation laws for free-boundary fluid layers
Creators: name: Bueler, Ed
Publisher: name: arXiv
Year: 2020
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics
subject: 35K86, 65K15, 76A20, 76D27, 76M12

description: Time-dependent models of fluid motion in thin layers, subject to signed source terms, represent important sub-problems within climate dynamics. Examples include ice sheets, sea ice, and even shallow oceans and lakes. We address these problems as discrete-time sequences of continuous-space weak formulations, namely (monotone) variational inequalities or complementarity problems, in which the conserved quantity is the layer thickness. Free boundaries wherein the thickness and mass flux both go to zero at the margin of the fluid layer generically arise in such models. After showing these problems are well-posed in several cases, we consider the limitations to discrete conservation in numerical schemes. A free boundary in a region of negative source -- an ablation-caused margin -- turns out to be a barrier to exact conservation in either a continuous- or discrete-space sense. We then propose computable a posteriori quantities which allow conservation-error bounds in finite volume and finite element schemes.
description: 26 pages, 4 figures
KISS-ICP: In Defense of Point-to-Point ICP -- Simple, Accurate, and Robust Registration If Done the Right Way
Creators: name: Vizzo, Ignacio
name: Guadagnino, Tiziano
name: Mersch, Benedikt
name: Wiesmann, Louis
name: Behley, Jens
name: Stachniss, Cyrill
Publisher: name: arXiv
Year: 2022
Subjects: subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: Robust and accurate pose estimation of a robotic platform, so-called sensor-based odometry, is an essential part of many robotic applications. While many sensor odometry systems made progress by adding more complexity to the ego-motion estimation process, we move in the opposite direction. By removing a majority of parts and focusing on the core elements, we obtain a surprisingly effective system that is simple to realize and can operate under various environmental conditions using different LiDAR sensors. Our odometry estimation approach relies on point-to-point ICP combined with adaptive thresholding for correspondence matching, a robust kernel, a simple but widely applicable motion compensation approach, and a point cloud subsampling strategy. This yields a system with only a few parameters that in most cases do not even have to be tuned to a specific LiDAR sensor. Our system using the same parameters performs on par with state-of-the-art methods under various operating conditions using different platforms: automotive platforms, UAV-based operation, vehicles like segways, or handheld LiDARs. We do not require integrating IMU information and solely rely on 3D point cloud data obtained from a wide range of 3D LiDAR sensors, thus, enabling a broad spectrum of different applications and operating conditions. Our open-source system operates faster than the sensor frame rate in all presented datasets and is designed for real-world scenarios.
description: 8 pages
Exact distributions of cover times for $N$ independent random walkers in one dimension
Creators: name: Majumdar, Satya N.
name: Sabhapandit, Sanjib
name: Schehr, Gregory
Publisher: name: arXiv
Year: 2016
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Probability (math.PR)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We study the probability density function (PDF) of the cover time $t_c$ of a finite interval of size $L$, by $N$ independent one-dimensional Brownian motions, each with diffusion constant $D$. The cover time $t_c$ is the minimum time needed such that each point of the entire interval is visited by at least one of the $N$ walkers. We derive exact results for the full PDF of $t_c$ for arbitrary $N \geq 1$, for both reflecting and periodic boundary conditions. The PDFs depend explicitly on $N$ and on the boundary conditions. In the limit of large $N$, we show that $t_c$ approaches its average value $\langle t_c \rangle \approx L^2/(16\, D \, \ln N)$, with fluctuations vanishing as $1/(\ln N)^2$. We also compute the centered and scaled limiting distributions for large $N$ for both boundary conditions and show that they are given by nontrivial $N$-independent scaling functions.
description: 5+2 pages, 4 figures
Axion-Polaritons in the Magnetic Dual Chiral Density Wave Phase of Dense QCD
Creators: name: Ferrer, Efrain J.
name: de la Incera, Vivian
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We investigate the propagation of electromagnetic radiation in the magnetic dual chiral density wave (MDCDW) phase of dense quark matter. Considering the theory of low-energy fluctuations in this phase, we show how linearly polarized photons reaching the MDCDW medium couple to the fluctuation field to produce two hybridized modes of propagation that we call in analogy with similar phenomenon in condensed matter physics axion polaritons, one of them being gapless and the other gapped. The gapped mode's gap is proportional to the background magnetic field and inversely proportional to the amplitude of the inhomogeneous condensate. The generation of axion polaritons can be traced back to the presence of the chiral anomaly in the low-energy theory of the fluctuations. Considering the Primakoff effect in the MDCDW medium, we argued that axion polaritons can be generated inside quark stars bombarded by energetic photons coming from gamma-ray bursts and point out that this mechanism could serve to explain the missing pulsar paradox in the galaxy center.
description: Some formulas were changed
A comparative study of the impacts of two regional universities on the human capital of their communities
Creators: name: Helal, Nagy
Publisher: name: Monash University
Year: 2021

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
Categories of quantum liquids I
Creators: name: Kong, Liang
name: Zheng, Hao
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Category Theory (math.CT)
subject: Quantum Algebra (math.QA)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We develop a mathematical theory of separable higher categories based on Gaiotto and Johnson-Freyd's work on condensation completion. Based on this theory, we prove some fundamental results on $E_m$-multi-fusion higher categories and their higher centers. We also outline a theory of unitary higher categories based on a $*$-version of condensation completion. After these mathematical preparations, based on the idea of topological Wick rotation, we develop a unified mathematical theory of all quantum liquids, which include topological orders, SPT/SET orders, symmetry-breaking orders and CFT-like gapless phases. We explain that a quantum liquid consists of two parts, the topological skeleton and the local quantum symmetry, and show that all $n$D quantum liquids form a $*$-condensation complete higher category whose equivalence type can be computed explicitly from a simple coslice 1-category.
description: 36 pages, a minor revision, including a correction of an typo in Theorem 5.5, an illustrative picture in Hypothesis 5.3 and refinement of a few sentences
Low-cost SiGe circuits for frequency synthesis in millimeter-wave devices
Creators: name: Lauterbach, Adam Peter
Publisher: name: Macquarie University
Year: 2022
Subjects: Other education not elsewhere classified

description: Advances in Silicon Germanium (SiGe) Bipolar Complementary Metal Oxide Semiconductor (BiCMOS) technology has caused a recent revolution in low-cost Monolithic Microwave Integrated Circuit (MMIC) design. -- This thesis presents the design, fabrication and measurement of four MMICs for frequency synthesis, manufactured in a commercially available IBM 0.18μm SiGe BiCMOS technology with ft = 60GHz. The high speed and low-cost features of SiGe Heterojunction Bipolar Transistors (HBTs) were exploited to successfully develop two single-ended injection-lockable 15GHz Voltage Controlled Oscillators (VCOs) for application in an active Ka-Band antenna beam-forming network, and a 24GHz differential cross-coupled VCO and 1/6 synchronous static frequency prescaler for emerging Ultra Wideband (UWB) automotive Short Range Radar (SRR) applications. -- On-wafer measurement techniques were used to precisely characterise the performance of each circuit and compare against expected simulation results and state-of-the-art performance reported in the literature. -- The original contributions of this thesis include the application of negative resistance theory to single-ended and differential SiGe VCO design at 15-24GHz, consideration of manufacturing process variation on 24GHz VCO and prescaler performance, implementation of a fully static multi-stage synchronous divider topology at 24GHz and the use of differential on-wafer measurement techniques. -- Finally, this thesis has llustrated the excellent practicability of SiGe BiCMOS technology in the engineering of high performance, low-cost MMICs for frequency synthesis in millimeterwave (mm-wave) devices.
Investigating the behavior of deep convolution networks in image recognition
Creators: name: Hajaj, Mohamed
Publisher: name: Imperial College London
Year: 2018

description: This research project investigates the role of key factors that led to the resurgence of deep CNNs and their success in classifying large datasets of natural images. Our investigation included the role of new network components, the role of the training data, and the role of data augmentation. Investigating the role of data augmentation led to the successful implementation of a deep CNN that can be trained using a variable input size, which increased the amount of allowable scale augmentation and led to much better single-view performance. Our analysis of the role of the training data shows the capabilities of deep CNNs to break down a large hierarchical dataset along the hierarchical lines into smaller components and learn all of them with great efficiency. This might help explain why deep CNN are very effective in classifying large and dense datasets of natural images which tend to have a hierarchical structure. Our investigation of core network components shows that the shared normalisation statistics of BN allowed us to alter the behaviour of the network by controlling the structure of the training batches. We used this observation to obtain large conditional gain by training and testing the network using balanced batches. Finally, we were able to implement a successful multitasking network that were able to outperform the corresponding single task networks. Our model used the normalisation statistics of BN to separate between the tasks, and our analysis shows that using a whole dataset per task increases the gains of the multitasking network by increasing the transfer of knowledge between the tasks.
The Nehari problem for the Paley--Wiener space of a disc
Creators: name: Brevig, Ole Fredrik
name: Perfekt, Karl-Mikael
Publisher: name: arXiv
Year: 2022
Subjects: subject: Functional Analysis (math.FA)
subject: FOS: Mathematics

description: There is a bounded Hankel operator on the Paley--Wiener space of a disc in $\mathbb{R}^2$ which does not arise from a bounded symbol.
description: This paper has been accepted for publication in Journal of Geometric Analysis
MOA-II Galactic Microlensing Constraints: The Inner Milky Way has a Low Dark Matter Fraction and a Near Maximal Disk
Creators: name: Wegg, Christopher
name: Gerhard, Ortwin
name: Portail, Matthieu
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Microlensing provides a unique tool to break the stellar to dark matter degeneracy in the inner Milky Way. We combine N-body dynamical models fitted to the Milky Way's Boxy/Peanut bulge with exponential disk models outside this, and compute the microlensing properties. Considering the range of models consistent with the revised MOA-II data, we find low dark matter fractions in the inner Galaxy: at the peak of their stellar rotation curve a fraction $f_v=(0.88\pm0.07)$ of the circular velocity is baryonic (at $1σ$, $f_v > 0.72$ at $2σ$). These results are in agreement with constraints from the EROS-II microlensing survey of brighter resolved stars, where we find $f_v=(0.9\pm0.1)$ at $1σ$. Our fiducial model of a disk with scale length 2.6kpc, and a bulge with a low dark matter fraction of 12%, agrees with both the revised MOA-II and EROS-II microlensing data. The required baryonic fractions, and the resultant low contribution from dark matter, are consistent with the NFW profiles produced by dissipationless cosmological simulations in Milky Way mass galaxies. They are also consistent with recent prescriptions for the mild adiabatic contraction of Milky Way mass haloes without the need for strong feedback, but there is some tension with recent measurements of the local dark matter density. Microlensing optical depths from the larger OGLE-III sample could improve these constraints further when available.
description: 14 pages, 13 figures, submitted to MNRAS
Residues of manifolds
Creators: name: O'Hara, Jun
Publisher: name: arXiv
Year: 2020
Subjects: subject: Differential Geometry (math.DG)
subject: Metric Geometry (math.MG)
subject: FOS: Mathematics
subject: 53C65, 58A99, 52A38, 53A07

description: The Riesz $z$-energy of a manifold $X$ is the integration of the distance between two points to the power $z$ over the product space $X\times X$. Considered as a function of a complex variable $z$, it can be generalized to a meromorphic function by analytic continuation, which we will call the meromorphic energy function of $X$. It has only simple poles at some negative integers. The residues of a manifold $X$ are the residues of the meromorphic energy function. For example, the volume and the Willmore energy for surfaces in $\mathbb{R}^3$ can be obtained as residues. In this paper we first show the Möbius invariance of the residue at $z=-2\dim X$ of a closed submanifold or a compact body in a Euclidean space. We introduce the relative residues for compact bodies and weighted residues, and show that the scalar curvature and the mean curvature as well as the Euler characteristic of compact bodies of dimension less than $4$ can be expressed in terms of residues and local residues. We study the order of differentiaion of a local defining function of $X$ that is necessary to obtain the (global) residues when $X$ is a closed submanifold of a Euclidean space. We also show the inclusion-exclusion principle. Residues appear to be similar to quantities obtained by asymptotic expansion such as intrinsic volumes (Lipschitz-Killing curvatures), spectra of Laplacian, and the Graham-Witten energy. We show that residues are independent from them. Finally we introduce a \M invariant principal curvature energy for $4$-dimensional hypersurfaces in $\mathbb{R}^5$, and express the Graham-Witten energy in terms of the residues, Weyl tensor, and this Möbius invariant principal curvature energy.
description: 51 pages
Physical realization of a quantum spin liquid based on a novel frustration mechanism
Creators: name: Balz, Christian
name: Lake, Bella
name: Reuther, Johannes
name: Luetkens, Hubertus
name: Schönemann, Rico
name: Herrmannsdörfer, Thomas
name: Singh, Yogesh
name: Islam, A. T. M. Nazmul
name: Wheeler, Elisa M.
name: Rodriguez-Rivera, Jose A.
name: Guidi, Tatiana
name: Simeoni, Giovanna G.
name: Baines, Chris
name: Ryll, Hanjo
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Unlike conventional magnets where the magnetic moments are partially or completely static in the ground state, in a quantum spin liquid they remain in collective motion down to the lowest temperatures. The importance of this state is that it is coherent and highly entangled without breaking local symmetries. Such phenomena is usually sought in simple lattices where antiferromagnetic interactions and/or anisotropies that favor specific alignments of the magnetic moments are "frustrated" by lattice geometries incompatible with such order e.g. triangular structures. Despite an extensive search among such compounds, experimental realizations remain very few. Here we describe the investigation of a novel, unexplored magnetic system consisting of strong ferromagnetic and weaker antiferromagnetic isotropic interactions as realized by the compound Ca$_{10}$Cr$_7$O$_{28}$. Despite its exotic structure we show both experimentally and theoretically that it displays all the features expected of a quantum spin liquid including coherent spin dynamics in the ground state and the complete absence of static magnetism.
description: Modified version accepted in Nature Physics
Sedimentary and volcaniclastic record of a mid-ocean spreading ridge: Macquarie Island, Southern Ocean
Creators: name: Portner, Ryan Adam
Publisher: name: Macquarie University
Year: 2022
Subjects: Other education not elsewhere classified

description: Sedimentary and volcaniclastic rocks formed within mid-ocean ridge spreading centers have received relatively little documentation compared to their counterparts found in continental margin and volcanic arc systems. Results presented in this thesis characterize a diverse sedimentary and volcaniclastic lithofacies assemblage exposed on the Macquarie Island ophiolite, which formed within a waning slow-spreading mid-ocean ridge. Petrography, geochemistry, and geochronology of detritus indicate that the sedimentary rocks were derived from submarine exposures of faulted Oligocene to Miocene age oceanic crust. The interaction of fault-derived gravity flows with a rugged mid-ocean ridge sea floor and strong bottom current of the Southern Ocean produced a unique depositional environment. Low grade zeolite metamorphism and in-situ uplift of Macquarie Island sedimentary rocks aided the preservation of delicate sedimentary structures otherwise deformed during continental obduction or drilling of modern day midoceanridge sediment. Isotope and trace element geochemistry of sandstone, gabbroic colluvium, and basalt indicates that Miocene Macquarie Island crust was derived from a much more enriched mantle source compared to the Oligocene age detritus. The recorded covariance in enrichment with time may be attributed to changes in spreading direction and shortening of spreading segments. Alternatively, long-offset transforms associated with the shortened segments likely separated a heterogeneous mantle source. This is supported by paleogeographic reconstructions that show >300km of offset between sources for the Oligocene detritus and Macquarie Island crust. Long-offset transforms along the waning spreading center also played a role in limiting magma mixing, which is preserved by geochemically variable sideromelanein volcaniclastic rocks. Distinct geochemistry within individual volcaniclastic rock units is attributed to discrete eruption episodes, which were primarily associated with non-explosive quench fragmentation processes along the steep slopes of growing pillow cones and active fault scarps. Rare explosive eruptions also occurred in relatively enriched magma compositions containing both fractionated and volatile components.
Probing nonstandard neutrino cosmology with terrestrial neutrino experiments
Creators: name: Ghalsasi, Akshay
name: McKeen, David
name: Nelson, Ann E.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Neutrino masses and the number of light neutrino species can be tested in a variety of laboratory experiments and also can be constrained by particle astrophysics and precision cosmology. A conflict between these various results could be an indication of new physics in the neutrino sector. In this paper we explore the possibility for reconciliation of otherwise discrepant results in a simple model containing a light scalar field which produces Mass Varying Neutrinos (MaVaNs). We extend previous work on MaVaNs to consider issues of neutrino clumping, the effects of additional contributions to neutrino mass, and reconciliation of eV mass sterile neutrinos with cosmology.
description: 10 pages, 4 figures
A generalized conditional gradient method for dynamic inverse problems with optimal transport regularization
Creators: name: Bredies, Kristian
name: Carioni, Marcello
name: Fanzon, Silvio
name: Romero, Francisco
Publisher: name: arXiv
Year: 2020
Subjects: subject: Numerical Analysis (math.NA)
subject: Optimization and Control (math.OC)
subject: FOS: Mathematics
subject: 65K10, 65J20, 90C49, 28A33, 35F05

description: We develop a dynamic generalized conditional gradient method (DGCG) for dynamic inverse problems with optimal transport regularization. We consider the framework introduced in (Bredies and Fanzon, ESAIM: M2AN, 54:2351-2382, 2020), where the objective functional is comprised of a fidelity term, penalizing the pointwise in time discrepancy between the observation and the unknown in time-varying Hilbert spaces, and a regularizer keeping track of the dynamics, given by the Benamou-Brenier energy constrained via the homogeneous continuity equation. Employing the characterization of the extremal points of the Benamou-Brenier energy (Bredies et al., arXiv:1907.11589, 2019) we define the atoms of the problem as measures concentrated on absolutely continuous curves in the domain. We propose a dynamic generalization of a conditional gradient method that consists in iteratively adding suitably chosen atoms to the current sparse iterate, and subsequently optimize the coefficients in the resulting linear combination. We prove that the method converges with a sublinear rate to a minimizer of the objective functional. Additionally, we propose heuristic strategies and acceleration steps that allow to implement the algorithm efficiently. Finally, we provide numerical examples that demonstrate the effectiveness of our algorithm and model at reconstructing heavily undersampled dynamic data, together with the presence of noise.
description: 40 pages, 8 figures, 1 table
Effectiveness of pre-vocational training with cognitive behavioural therapy on general health, locus of control, work potential and employment status : a controlled evaluation
Creators: name: Storme, Brooklyn
Publisher: name: Monash University
Year: 2021

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
Nonequilibrium relaxation of a trapped particle in a near-critical Gaussian field
Creators: name: Venturelli, Davide
name: Ferraro, Francesco
name: Gambassi, Andrea
Publisher: name: arXiv
Year: 2022
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We study the non-equilibrium relaxational dynamics of a probe particle linearly coupled to a thermally fluctuating scalar field and subject to a harmonic potential, which provides a cartoon for an optically trapped colloid immersed in a fluid close to its bulk critical point. The average position of the particle initially displaced from the position of mechanical equilibrium is shown to feature long-time algebraic tails as the critical point of the field is approached, the universal exponents of which are determined in arbitrary spatial dimensions. As expected, this behavior cannot be captured by adiabatic approaches which assume fast field relaxation. The predictions of the analytic, perturbative approach are qualitatively confirmed by numerical simulations.
description: 33 pages, 11 figures
Fully nonlinear gravitational instabilities for expanding Newtonian universes with inhomogeneous pressure and entropy: Beyond the Tolman's solution
Creators: name: Liu, Chao
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: Nonlinear gravitational instability is a crucial way to comprehend the clustering of matter and the formation of nonlinear structures in both the Universe and stellar systems. However, with the exception of a few exact particular solutions for pressureless matter, there are only some approximations and numerical and phenomenological approaches to study the nonlinear gravitational instability instead of mathematically rigorous analysis. We construct a family of particular solutions of the Euler-Poisson system that exhibits the nonlinear gravitational instability of matter with inhomogeneous pressure and entropy (i.e., the cold center and hot rim) in the expanding Newtonian universe. Despite the density perturbations being homogeneous, the pressure is not, resulting in significant nonlinear effects. By making use of our prior work on nonlinear analysis of a class of differential equations \cite{Liu2022b}, we estimate that the growth rate of the density contrast is approximately $\sim \exp(t^{\frac{2}{3}})$, much faster than the growth rate anticipated by classical linear Jeans instability ($\sim t^{\frac{2}{3}}$). Our main motivation for constructing this family of solutions is to provide a family of reference solutions for conducting a fully nonlinear analysis of inhomogeneous perturbations of density contrast. We will present the general results in a mathematical article \cite{Liu2023b} separately. Additionally, we emphasize that our model does not feature any shell-crossing singularities before mass accretion singularities since we are specifically interested in analyzing the mathematical mechanics of a pure mass accretion model, which poses limitations on the applicability of our model for understanding the realistic nonlinear structure formation.
description: 18 pages, The title has been changed from v2 and v1 has been significantly rewritten. Material added in v3 to address referee comments. Agrees with the published version