cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Consequences of longitudinal coupled-bunch instability mitigation on power requirements during the HL-LHC filling
Creators: name: Karpov, I.
name: Baudrenghien, P.
name: Medina Medrano, L.E.
name: Timko, H.
Publisher: name: CERN Yellow Reports: Conference Proceedings
Year: 2020

description: During the filling of the Large Hadron Collider (LHC), it is desirable to keep the RF cavity voltage constant both in amplitude and phase to minimize the emittance blow-up and injection losses. To have a constant voltage and to minimize power consumption, a special beam-loading compensation scheme called half-detuning is used in the LHC, for which the cavity fundamental resonant frequency needs to be de-tuned from the RF frequency by an appropriate value. This, however, can result in fast coupled-bunch instabilities caused by the asymmetry of the fundamental cavity impedance. To mitigate them, a fast direct RF feedback and a one-turn delay feedback are presently used in the LHC. The semi-analytical model that describes the dynamics of the Low-Level RF system in the LHC shows that, depending on the mitigation scenario, the required transient RF power during injection could significantly exceed the steady-state value. This means that for High-Luminosity LHC (HL-LHC) beam intensities, one can potentially reach the limit of available RF power. In this paper, the model is described, and benchmarks with LHC measurements are presented. We also shortly revisit the damping requirements for the longitudinal coupled-bunch instability at injection energy, to find a compromise between longitudinal stability and RF power requirements for the HL-LHC beam.
description: CERN Yellow Reports: Conference Proceedings, Vol. 9 (2020): Proceedings of the ICFA mini-Workshop on Mitigation of Coherent Beam Instabilities in Particle Accelerators, Zermatt, Switzerland, 23–27 September 2019
The Cutkosky rule of three dimensional noncommutative field theory in Lie algebraic noncommutative spacetime
Creators: name: Sasai, Yuya
name: Sasakura, Naoki
Publisher: name: arXiv
Year: 2009
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We investigate the unitarity of three dimensional noncommutative scalar field theory in the Lie algebraic noncommutative spacetime [x^i,x^j]=2i kappa epsilon^{ijk}x_k. This noncommutative field theory possesses a SL(2,R)/Z_2 group momentum space, which leads to a Hopf algebraic translational symmetry. We check the Cutkosky rule of the one-loop self-energy diagrams in the noncommutative phi^3 theory when we include a braiding, which is necessary for the noncommutative field theory to possess the Hopf algebraic translational symmetry at quantum level. Then, we find that the Cutkosky rule is satisfied if the mass is less than 1/(2^(1/2)kappa).
description: 24 pages, 13 figures, a minor clarification, references added
Defect of irreducible plane curves with simple singularities
Creators: name: Pokora, Piotr
Publisher: name: arXiv
Year: 2024
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics

description: In this note we focus on the defect of singular plane curve that was recently introduced by Dimca. Roughly speaking, the defect of a reduced plane curve measures the discrepancy from the property of being a free curve. We find some lower-bound on the defect for certain classes of irreducible plane curves admitting nodes, ordinary cusps and ordinary triple points. The main result of the note tells us that reduced simply singular plane curves with sufficiently high Arnold exponents are never free.
description: 9 pages, to appear in Annales Polonici Mathematici (a special volume dedicated to the memory of Arkadiusz Ploski)
Continual Policy Distillation of Reinforcement Learning-based Controllers for Soft Robotic In-Hand Manipulation
Creators: name: Li, Lanpei
name: Donato, Enrico
name: Lomonaco, Vincenzo
name: Falotico, Egidio
Publisher: name: arXiv
Year: 2024
Subjects: subject: Robotics (cs.RO)
subject: Artificial Intelligence (cs.AI)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Dexterous manipulation, often facilitated by multi-fingered robotic hands, holds solid impact for real-world applications. Soft robotic hands, due to their compliant nature, offer flexibility and adaptability during object grasping and manipulation. Yet, benefits come with challenges, particularly in the control development for finger coordination. Reinforcement Learning (RL) can be employed to train object-specific in-hand manipulation policies, but limiting adaptability and generalizability. We introduce a Continual Policy Distillation (CPD) framework to acquire a versatile controller for in-hand manipulation, to rotate different objects in shape and size within a four-fingered soft gripper. The framework leverages Policy Distillation (PD) to transfer knowledge from expert policies to a continually evolving student policy network. Exemplar-based rehearsal methods are then integrated to mitigate catastrophic forgetting and enhance generalization. The performance of the CPD framework over various replay strategies demonstrates its effectiveness in consolidating knowledge from multiple experts and achieving versatile and adaptive behaviours for in-hand manipulation tasks.
description: Accepted for presentation at IEEE RoboSoft 2024
Nuclear physics for geo-neutrino studies
Creators: name: Fiorentini, Gianni
name: Ianni, Aldo
name: Korga, George
name: Lissia, Marcello
name: Mantovani, Fabio
name: Miramonti, Lino
name: Oberauer, Lothar
name: Obolensky, Michel
name: Smirnov, Oleg
name: Suvorov, Yury
Publisher: name: arXiv
Year: 2009
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: Nuclear Theory (nucl-th)
subject: Geophysics (physics.geo-ph)
subject: FOS: Physical sciences

description: Geo-neutrino studies are based on theoretical estimates of geo-neutrino spectra. We propose a method for a direct measurement of the energy distribution of antineutrinos from decays of long-lived radioactive isotopes. We present preliminary results for the geo-neutrinos from Bi-214 decay, a process which accounts for about one half of the total geo-neutrino signal. The feeding probability of the lowest state of Bi-214 - the most important for geo-neutrino signal - is found to be p_0 = 0.177 \pm 0.004 (stat) ^{+0.003}_{-0.001} (sys), under the hypothesis of Universal Neutrino Spectrum Shape (UNSS). This value is consistent with the (indirect) estimate of the Table of Isotopes (ToI). We show that achievable larger statistics and reduction of systematics should allow to test possible distortions of the neutrino spectrum from that predicted using the UNSS hypothesis. Implications on the geo-neutrino signal are discussed.
description: 8 pages RevTex format, 8 figures and 2 tables. Submitted to PRC
Synchronous phase shift measurements for evaluation of the longitudinal impedance model at the CERN SPS
Creators: name: Schwarz, M.
name: Farricker, A.
name: Karpov, I.
name: Lasheen, A.
Publisher: name: CERN Yellow Reports: Conference Proceedings
Year: 2020

description: The High Luminosity LHC (HL-LHC) requires 2.3 × 1011 protons per bunch (ppb) at LHC injection. For the SPS, the injector to the LHC, this goal requires a doubling of the injected intensity to 2.6 × 1011 ppb. Longitudinal instabilities were observed in the SPS for intensities below the required 2.6 × 1011 ppb. Identifying, and ultimately mitigating, the impedance sources driving the instabilities requires an accurate impedance model. Here, we report on measurements of the synchronous phase shift with intensity and corresponding energy loss at the SPS injection. Using the loss factor to compute the energy loss from the measured bunch spectrum and the SPS impedance model leads to significant disagreements with measurements. This issue is investigated for the simplified case of a single resonator. However, simulating matched bunches using the SPS impedance model yields better agreement with measurements.
description: CERN Yellow Reports: Conference Proceedings, Vol. 9 (2020): Proceedings of the ICFA mini-Workshop on Mitigation of Coherent Beam Instabilities in Particle Accelerators, Zermatt, Switzerland, 23–27 September 2019
Cloud Migration: A Case Study of Migrating an Enterprise IT System to IaaS
Creators: name: Khajeh-Hosseini, Ali
name: Greenwood, David
name: Sommerville, Ian
Publisher: name: arXiv
Year: 2010
Subjects: subject: Distributed, Parallel, and Cluster Computing (cs.DC)
subject: FOS: Computer and information sciences

description: This case study illustrates the potential benefits and risks associated with the migration of an IT system in the oil & gas industry from an in-house data center to Amazon EC2 from a broad variety of stakeholder perspectives across the enterprise, thus transcending the typical, yet narrow, financial and technical analysis offered by providers. Our results show that the system infrastructure in the case study would have cost 37% less over 5 years on EC2, and using cloud computing could have potentially eliminated 21% of the support calls for this system. These findings seem significant enough to call for a migration of the system to the cloud but our stakeholder impact analysis revealed that there are significant risks associated with this. Whilst the benefits of using the cloud are attractive, we argue that it is important that enterprise decision-makers consider the overall organizational implications of the changes brought about with cloud computing to avoid implementing local optimizations at the cost of organization-wide performance.
description: Submitted to IEEE CLOUD 2010
Herbert Knittler zu seinem nunmehr 68. Geburtstag
Creators: name: Stekl, Hannes
Publisher: name: Jahrbuch für Geschichte des ländlichen Raumes
Year: 2022

description: Jahrbuch für Geschichte des ländlichen Raumes, Bd. 6 (2009): Zwischen Land und Stadt. Wirtschaftsverflechtungen von ländlichen und städtischen Räumen in Europa 1300–1600
Faraday Waves in Bose-Einstein Condensates -- The Excitation by the Modulation of the Interaction and the Potential
Creators: name: Shukuno, Nobuyuki
name: Sano, Yuto
name: Tsubota, Makoto
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: We numerically study the dynamics of Faraday waves for Bose-Einstein condensates(BECs) trapped by anisotropic potentials using the three-dimensional Gross-Pitaevskii equation. In previous studies, Faraday waves were excited by periodic modulation of the interaction or potential; in contrast, this study systematically addresses the excitations of the two methods. When the interaction is modulated with a modulation frequency resonant with Faraday waves, the breathing mode along the tight confinement direction is excited, and the Faraday waves appear in the direction of weak confinement. A modulation frequency that is not resonant with Faraday waves does not excite Faraday waves. Thus, the dynamics depend on modulation frequencies. The behavior of the total energy and its decomposition characterize the dynamics. The excitation of Faraday waves depends on the anisotropy of the potentials as well; Faraday waves are excited only for elongated BECs. We compare the differences of the dynamics in modulation methods. There are no qualitative differences between the modulation of the interaction and potential. When the interaction and potential are simultaneously modulated, Faraday waves are excited but they do not necessarily work additively. To understand this phenomenon as a dynamical system, we choose a few dynamical variables and follow their trajectory in a phase space. The trajectory characteristics of Faraday waves and the breathing mode show that the methods of modulation are not very relevant; determining the target mode to excite is important.
description: 7 pages, 14 figures
Multi-modal perception for soft robotic interactions using generative models
Creators: name: Donato, Enrico
name: Falotico, Egidio
name: Thuruthel, Thomas George
Publisher: name: arXiv
Year: 2024
Subjects: subject: Robotics (cs.RO)
subject: Artificial Intelligence (cs.AI)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Perception is essential for the active interaction of physical agents with the external environment. The integration of multiple sensory modalities, such as touch and vision, enhances this perceptual process, creating a more comprehensive and robust understanding of the world. Such fusion is particularly useful for highly deformable bodies such as soft robots. Developing a compact, yet comprehensive state representation from multi-sensory inputs can pave the way for the development of complex control strategies. This paper introduces a perception model that harmonizes data from diverse modalities to build a holistic state representation and assimilate essential information. The model relies on the causality between sensory input and robotic actions, employing a generative model to efficiently compress fused information and predict the next observation. We present, for the first time, a study on how touch can be predicted from vision and proprioception on soft robots, the importance of the cross-modal generation and why this is essential for soft robotic interactions in unstructured environments.
description: Accepted for presentation at IEEE RoboSoft 2024
Identification of impedance sources responsible for longitudinal beam instabilities in the CERN PS
Creators: name: Lasheen, A.
name: Damerau, H.
name: Favia, G.
name: Kozlowski, P.
name: Popovic, B.
Publisher: name: CERN Yellow Reports: Conference Proceedings
Year: 2020

description: Longitudinal instabilities in the CERN PS are an important limitation to obtain the expected beam intensity and longitudinal emittance at the PS extraction in the framework of the LHC Injector Upgrade (LIU) project. The observed coupled-bunch instabilities lead to dipolar and quadrupolar oscillations, as well as to an uncontrolled longitudinal emittance blow-up for proton beams. A microwave instability observed with ion beams develops quickly at transition crossing. To identify the potential impedance sources of these instabilities, two strategies were adopted. Firstly, beam measurements were performed for dierent impedance configurations, i.e. by partially detuning the main RF cavities. Secondly, a thorough survey of the machine elements together with the RF studies allowed to refine the PS impedance model in order to find potentially missing contributions. Measurements were compared with particle simulations using the updated impedance model of the PS. Although the source of the dipolar coupled-bunch instability was already identified in the past, this study led to an identification of the impedance sources driving other types of longitudinal instabilities.
description: CERN Yellow Reports: Conference Proceedings, Vol. 9 (2020): Proceedings of the ICFA mini-Workshop on Mitigation of Coherent Beam Instabilities in Particle Accelerators, Zermatt, Switzerland, 23–27 September 2019
Majanduspoliitika teaduskonverentsid Eestis (1984-2011). Wissenschaftliche Konferenzen über Wirtschaftspolitik in Estland (1984-2011). Scientific conferences on economic policy in Estonia (1984-2011)
Creators: name: Raudjärv, Matti
Publisher: name: MATTIMAR OÜ
Year: 2012

description: Estonian Discussions on Economic Policy, Vol 19, No 1 (2011)
Noise-assisted spike propagation in myelinated neurons
Creators: name: Ochab-Marcinek, Anna
name: Schmid, Gerhard
name: Goychuk, Igor
name: Hänggi, Peter
Publisher: name: arXiv
Year: 2008
Subjects: subject: Neurons and Cognition (q-bio.NC)
subject: FOS: Biological sciences

description: We consider noise-assisted spike propagation in myelinated axons within a multi-compartment stochastic Hodgkin-Huxley model. The noise originates from a finite number of ion channels in each node of Ranvier. For the subthreshold internodal electric coupling, we show that (i) intrinsic noise removes the sharply defined threshold for spike propagation from node to node, and (ii) there exists an optimum number of ion channels which allows for the most efficient signal propagation and it corresponds to the actual physiological values.
description: 8 pages, 12 figures, accepted for publication in Phys. Rev. E
Surface Geometric and Electronic Structure of BaFe2As2(001)
Creators: name: Nascimento, V. B.
name: Li, Ang
name: Jayasundara, Dilushan R.
name: Xuan, Yi
name: O'Neal, Jared
name: Pan, Shuheng
name: Chien, T. Y.
name: Hu, Biao
name: He, X. B.
name: Li, Guorong
name: Sefat, A. S.
name: McGuire, M. A.
name: Sales, B. C.
name: Mandrus, D.
name: Pan, M. H.
name: Zhang, Jiandi
name: Jin, R.
name: Plummer, E. W.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: BaFe2As2 exhibits properties characteristic of the parent compounds of the newly discovered iron (Fe)-based high-TC superconductors. By combining the real space imaging of scanning tunneling microscopy/spectroscopy (STM/S) with momentum space quantitative Low Energy Electron Diffraction (LEED) we have identified the surface plane of cleaved BaFe2As2 crystals as the As terminated Fe-As layer - the plane where superconductivity occurs. LEED and STM/S data on the BaFe2As2(001) surface indicate an ordered arsenic (As) - terminated metallic surface without reconstruction or lattice distortion. It is surprising that the STM images the different Fe-As orbitals associated with the orthorhombic structure, not the As atoms in the surface plane.
description: 12 pages, 4 figures
Photo-induced Multiply Quantized Vortex States in Dirac-like Materials
Creators: name: Massaro, Lauren I.
name: Meese, Connor
name: Sandler, Nancy P.
name: Asmar, Mahmoud M.
Publisher: name: arXiv
Year: 2024
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Subjecting a massive two-dimensional Dirac material to a vortex light beam provides a mechanism for the photo-induction of multiply quantized vortices. Using Floquet theory, we show that electronic vortices, characterized by their total angular momentum, are exclusive to circularly polarized vortex beams. The equations for the driven system at the one photon-resonance are mapped to the Bogoliubov-de Gennes equations of $s$-wave superconductors with multiply quantized vortices. This mapping provides valuable analytical tools for the analysis of the system's spectral properties.
description: The supplementary material has been added
Vlasov solvers and simulation code analysis for mode coupling instabilities in both longitudinal and transverse planes
Creators: name: Métral, E.
name: Migliorati, M.
Publisher: name: CERN Yellow Reports: Conference Proceedings
Year: 2020

description: Two Vlasov solvers for the longitudinal and transverse planes are used to study the frequency shift of coherent oscillation modes and possible mode coupling instability for the two cases of a proton bunch interacting with either a constant inductive or a broad-band resonator impedance. In parallel to this approach, a new method to study the coherent frequency shift from the results of simulation codes is presented. Comparisons between the two methods are discussed, as well as simple analytical formulae (valid in the “long-bunch” regime), which clearly reveal how to mitigate these instabilities.
description: CERN Yellow Reports: Conference Proceedings, Vol. 9 (2020): Proceedings of the ICFA mini-Workshop on Mitigation of Coherent Beam Instabilities in Particle Accelerators, Zermatt, Switzerland, 23–27 September 2019
Cross Section and Tensor Analysing Power of the $\vec{d}d\to ηα$ Reaction Near Threshold
Creators: name: The GEM Collaboration
name: Budzanowski, A.
name: Chatterjee, A.
name: Gebel, R.
name: Hawranek, P.
name: Jahn, R.
name: Jha, V.
name: Kilian, K.
name: Kliczewski, S.
name: Kirillov, Da.
name: Kirillov, Di.
name: Kolev, D.
name: Kravcikova, M.
name: Lesiak, M.
name: Lieb, J.
name: Machner, H.
name: Magiera, A.
name: Maier, R.
name: Martinska, G.
name: Nedev, S.
name: Piskunov, N.
name: Prasuhn, D.
name: Protić, D.
name: Ritman, J.
name: von Rossen, P.
name: Roy, B. J.
name: Sitnik, U.
name: Siudak, R.
name: Tsenov, R.
name: Urban, J.
name: Vankova, G.
name: Wilkin, C.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: The angular distributions of the unpolarised differential cross section and tensor analysing power $A_{xx}$ of the $\vec{d}d\toαη$ reaction have been measured at an excess energy of 16.6 MeV. The ambiguities in the partial-wave description of these data are made explicit by using the invariant amplitude decomposition. This allows the magnitude of the s-wave amplitude to be extracted and compared with results published at lower energies. In this way, firmer bounds could be obtained on the scattering length of the $ηα$ system. The results do not, however, unambiguously prove the existence of a quasi-bound $ηα$ state.
description: 20 pages, 11 figures
SUVR: A Search-based Approach to Unsupervised Visual Representation Learning
Creators: name: Xu, Yi-Zhan
name: Chen, Chih-Yao
name: Li, Cheng-Te
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Unsupervised learning has grown in popularity because of the difficulty of collecting annotated data and the development of modern frameworks that allow us to learn from unlabeled data. Existing studies, however, either disregard variations at different levels of similarity or only consider negative samples from one batch. We argue that image pairs should have varying degrees of similarity, and the negative samples should be allowed to be drawn from the entire dataset. In this work, we propose Search-based Unsupervised Visual Representation Learning (SUVR) to learn better image representations in an unsupervised manner. We first construct a graph from the image dataset by the similarity between images, and adopt the concept of graph traversal to explore positive samples. In the meantime, we make sure that negative samples can be drawn from the full dataset. Quantitative experiments on five benchmark image classification datasets demonstrate that SUVR can significantly outperform strong competing methods on unsupervised embedding learning. Qualitative experiments also show that SUVR can produce better representations in which similar images are clustered closer together than unrelated images in the latent space.
description: ICASSP 2023
A neural network account to Kant's philosophical aesthetics
Creators: name: Graben, Peter beim
Publisher: name: arXiv
Year: 2024
Subjects: subject: Neurons and Cognition (q-bio.NC)
subject: FOS: Biological sciences

description: According to Kant's (1724 -- 1804) philosophical aesthetics, laid down in his Critique of the Power of Judgement (1790), beauty is "subjective purposefulness", reflected by the "harmony of the cognitive faculties", which are "understanding" and "imagination". On the one hand, understanding refers to the mental capability to find regularities in sensory manifolds, while imagination refers to intuition, fantasy, and creativity of the mind, on the other hand. Inspired by the reinforcement learning theory of Schmidhuber, I present a neural network analogy for the harmony of the faculties in terms of generative adversarial networks (GAN) - also often employed for artificial music composition -- by identifying the generator module with the faculty of imagination and the discriminator module with the faculty of understanding. According to the GAN algorithm, both modules are engaged in an adversarial game, thereby optimizing a particular objective function. In my reconstruction, the convergence of the GAN algorithm during the reception of art, either music or fine, entails the harmony of the faculties and thereby a neural network analogue of subjective purposefulness, i.e., beauty.
description: 33 pages, 3 figures
Total synthesis of certain hydrochrysene analogues
Creators: name: Roller, Peter Paul
Publisher: name: University of British Columbia
Year: 2011

description: Two sequences leading to the total synthesis of several octahydrochrysene derivatives are described; in particular, the synthesis of B-nor-cis-2-methoxy-8α-acetoxy-5-keto-10a-methyl-5,6,7,8,9,10,10a-octahydrochrysene (XL) is achieved. In one sequence an olefinic bond at the 5,6 position of ring B (XXXII) was introduced by reduction of cis-2-methoxy-8α-acetoxy-5-keto-10a-methyl-5,6,6a, 7,8,9,10,lOa-octahydrochrysene (XIV) with sodium borohydride, followed by dehydration with phosphorus pentoxide.Subsequent reaction at the olefinic linkage by osmium tetroxide provided the α-diol (XXX), which upon treatment with periodic acid yielded a hemiacetal (XXXIV). Cyclization on alumina then provided the B-nor internal aldol condensation product (XXXIX). The latter readily underwent / oxidation with Jones' reagent to result in the B-nor-5-keto acetate (XL). In an alternate sequence the cis-2-methoxy-8α-acetoxy-5-keto-5,6,6a,7,8, 9,10, 10a-octahydrochrysene (XIV) is oximinated at the 6-position with isoamyl nitrite and the oxime is converted by acid hydrolysis to a 5,6-diketo-8-hydroxy compound (XLII). An attempt was made to accomplish a benzilic acid rearrangement on the α-diketo compound and the resulting product (XLVII) was subjected to lead tetra-acetate oxidation in the hope that the B-nor-5-keto system (XLVIII) could be obtained. The structures from the last two reactions were only tentatively established. A critical discussion of the n.m.r. data is reserved to a separate section of the thesis. Tentative assignments of all the aromatic protons were made. Of special note is the chemical shift dependence of the proton at C₄ on the substitution at C₅. Configurational and conformational assignments of the ring A/B system were made on the basis of angular methyl and 8β-proton frequencies.
Confronting the dark matter capture rate with a continuous gravitational wave probe of local neutron stars
Creators: name: Bhattacharjee, Pooja
name: Banik, Amit Dutta
Publisher: name: arXiv
Year: 2024
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Continuous gravitational waves (CGWs) from various astrophysical sources are one of the many future probes of upcoming gravitational wave (GW) search missions. Neutron stars (NSs) with deformity are one of the leading sources of CGW emissions. In this work, for the first time, a novel attempt to estimate the dark matter (DM) capture rate is performed using CGW as the probe to the local NS population. Competitive bounds on DM capture from the local NS population are reported when compared with DM direct search experiments and other astrophysical observations.
description: 19 pages, 1 table, 5 figures
Brane Dynamics and 3D Seiberg Duality on the Domain Walls of 4D N=1 SYM
Creators: name: Armoni, Adi
name: Giveon, Amit
name: Israel, Dan
name: Niarchos, Vasilis
Publisher: name: arXiv
Year: 2009
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study a three-dimensional U(k) Yang-Mills Chern-Simons theory with adjoint matter preserving two supersymmetries. According to Acharya and Vafa, this theory describes the low-energy worldvolume dynamics of BPS domain walls in four-dimensional N=1 SYM theory. We demonstrate how to obtain the same theory in a brane configuration of type IIB string theory that contains threebranes and fivebranes. A combination of string and field theory techniques allows us to re-formulate some of the well-known properties of N=1 SYM domain walls in a geometric language and to postulate a Seiberg-like duality for the Acharya-Vafa theory. In the process, we obtain new information about the dynamics of branes in setups that preserve two supersymmetries. Using similar methods we also study other N=1 CS theories with extra matter in the adjoint and fundamental representations of the gauge group.
description: 25 pages, 5 figures
Tidal reconstruction of neutron star mergers from their late inspiral
Creators: name: Pal, Souradeep
name: Nayak, K Rajesh
Publisher: name: arXiv
Year: 2024
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We investigate the measurement correlation between the effective spin and the effective tidal deformability in gravitational wave signals from binary neutron star mergers. To efficiently measure the effective tidal deformability parameter, we exploit the fact that the tidal effects in a binary system are prominent when the components are closer during the late-inspiral. Thus, we indicate to a computationally efficient strategy of extracting the tidal information compressed within seconds before the merger. We report our observations for \texttt{GW170817} and explore the suitability of our approach in the upcoming observation scenarios of the current and the future ground-based observatories. Fast and accurate measurements of the tidal deformability parameters can be used to inform astronomers in prioritizing the electromagnetic follow-up efforts for such sources.
Skyrme-QRPA calculations for low-lying excitation modes in deformed neutron-rich nuclei
Creators: name: Yoshida, Kenichi
Publisher: name: arXiv
Year: 2009
Subjects: subject: Nuclear Theory (nucl-th)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: Low-frequency modes of excitation in deformed neutron-rich nuclei are studied by means of the quasiparticle random-phase approximation on the Skyrme-Hartree-Fock-Bogoliubov mean field. We investigate the microscopic structure of the soft $K^π=0^{+}$ modes systematically in neutron-rich Magnesium isotopes with $N=22, 24, 26$ and 28 close to the drip line, and it is found that the strong collectivity in $^{34}$Mg and $^{40}$Mg is acquired due to the coherent coupling between the $β$ vibration and the pairing vibration of neutrons. Microscopic structure of the $K^π=2^{+}$ modes changes gradually associated with the location of the Fermi level of neutrons, and it is found that the proton particle-hole excitation generating the $γ-$vibrational mode in $^{24}$Mg continues to play a key role in the near-drip-line nucleus $^{40}$Mg. The low-frequency octupole excitations are also investigated and the microscopic mechanism for the enhancement of transition strengths is discussed.
description: Accepted for publication in Eur. Phys. J. A, as a contribution to the ENAM08 conference
Review of instabilities with ions or/and electrons and possible mitigations
Creators: name: Mether, L.
Publisher: name: CERN Yellow Reports: Conference Proceedings
Year: 2020

description: The presence of ions and electrons from gas ionization, photoemission or secondary emission is unavoidable in the vacuum chambers of high intensity accelerators and storage rings. Under suitable conditions, these ions and electrons can accumulate and drive the beams unstable. In this contribution, the mechanisms behind and the main conditions for ion and electron accumulation in the bunched beams are summarized. The characteristics of the induced instabilities, as well as common modelling techniques and mitigation strategies are reviewed. The possible interplays between ions and electrons are also discussed.
description: CERN Yellow Reports: Conference Proceedings, Vol. 9 (2020): Proceedings of the ICFA mini-Workshop on Mitigation of Coherent Beam Instabilities in Particle Accelerators, Zermatt, Switzerland, 23–27 September 2019
Studies of difluorophosphoric acid and its alkali metal salts
Creators: name: Reed, William
Publisher: name: University of British Columbia
Year: 2011

description: Difluorophosphoric acid was purified by a double distillation technique. Alkali metal difluorophosphates were prepared by reaction of the metal chlorides with purified difluorophosphoric acid; x-ray powder photographs and infra-red spectra of the salts were obtained. Electrical conductivity measurements were made on solutions of the alkali metal difluorophosphates in difluorophosphoric acid as solvent. The order of mobility of the alkali metal cations in this solvent was found to be Li>Na>K>Rb>Cs. Results indicate that the difluorophosphate ion does not conduct by a proton transfer process in this solvent. Conductimetric studies on solutions of a number of other compounds in difluorophosphoric acid are also reported.
Damping of spin waves
Creators: name: Wagner, David
name: Shokri, Masoud
name: Rischke, Dirk H.
Publisher: name: arXiv
Year: 2024
Subjects: subject: Nuclear Theory (nucl-th)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We show that, in ideal-spin hydrodynamics, the components of the spin tensor follow damped wave equations. The damping rate is related to nonlocal collisions of the particles in the fluid, which enter at first order in $\hbar$ in a semi-classical expansion. This rate provides an estimate for the timescale of spin equilibration and is computed by considering a system of spin-1/2 fermions interacting via a quartic self-interaction as well as via (screened) one-gluon exchange. It is found that the relaxation times of the components of the spin tensor can become very large compared to the usual dissipative timescales of the system. Our results suggest that the spin degrees of freedom in a heavy-ion collision may not be in equilibrium by the time of freeze-out, and thus should be treated dynamically.
description: 13 pages, 1 figure
Space charge effects for transverse collective instabilities in circular machines
Creators: name: Burov, A.
Publisher: name: CERN Yellow Reports: Conference Proceedings
Year: 2020

description: Fifty years ago, the first significant publication was presented on transverse collective instabilities of spacecharge-dominated beams in circular machines; it was a CERN preprint of G. Merle and D. Möhl “The stabilizing influence of nonlinear space charge on transverse coherent oscillations”. A relatively simple equation of motion was suggested there as something obvious. Although it was, strictly speaking, neither obvious nor even quite correct, as further studies have shown, it played and continues to play an extraordinarily important role. Thus, this anniversary adds a special flavor to the request of the workshop organizers to review the main results in this area of beam dynamics. Purporting to fulfill that, this paper is divided in two sections, on coasting and bunched beams respectfully. We rather rarely deal with coasting beams in circular machines, but still they deserve a special attention not only for themselves, but also as relatively simple configurations to start from and get some key ideas. This set of ideas includes a concept of rigid slices and strong space charge as its justification. Also, it includes inter-play of Landau damping (LD), space charge (SC) and octupoles, showing the importance of their polarity, in particular. These ideas, common for coasting and bunched beams, are presented in Sec. II and used in Sec. III. In the latter section, SC-modification of the transverse mode coupling instability (TMCI) is discussed, including paradoxes which were resolved in a discovery of convective instabilities. The goal of this paper is to present, in a compact way, the main results in the area of beam dynamics, specified by the subject, where both SC and wake field are important. To a certain degree, such a task cannot be free from some subjectivity and arbitrariness, and I beg pardon of those colleagues who will find some valuable results underrepresented or not presented at all.
description: CERN Yellow Reports: Conference Proceedings, Vol. 9 (2020): Proceedings of the ICFA mini-Workshop on Mitigation of Coherent Beam Instabilities in Particle Accelerators, Zermatt, Switzerland, 23–27 September 2019
Long-distance effects in rare and radiative K decays
Creators: name: Smith, Christopher
Publisher: name: arXiv
Year: 2009
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The electroweak structures of the FCNC-induced rare and radiative K decays are presented. While the former decays are sensitive to short-distance physics and offer exceptional probes for new physics, the latter are dominated by long-distance physics. Even so, they should not be set aside since they constitute essential ingredients to control the hadronic uncertainties occurring for the rare decays. This is illustrated by systematically reviewing the phenomenological strategies currently in use to cleanly predict the rare K decay rates in the Standard Model.
description: 9 pages. Talk given at the 2009 Kaon International Conference (KAON 2009), June 9 - 12, 2009, Tsukuba, Japan
On topological groups containing a Fréchet-Urysohn fan
Creators: name: Banakh, Taras
Publisher: name: arXiv
Year: 2009
Subjects: subject: General Topology (math.GN)
subject: Group Theory (math.GR)
subject: FOS: Mathematics
subject: 22A05, 22A15, 54H11

description: Suppose G is a topological group containing a (closed) topological copy of the Frechet-Urysohn fan. If G is a perfectly normal sequential space (a normal k-space) then every closed metrizable subset in $G$ is locally compact. Applying this result to topological groups whose underlying topological space can be written as a direct limit of a sequence of closed metrizable subsets, we get that every such a group either is metrizable or is homeomorphic to the product of a $k_ω$-space and a discrete space.
Time domain measurements of the sub-THz response of different coatings for beam pipe walls
Creators: name: Passarelli, A.
name: Andreone, A.
name: Vaccaro, V.G.
name: Masullo, M.R.
name: Papaphilippou, Y.
name: Corsini, R.
Publisher: name: CERN Yellow Reports: Conference Proceedings
Year: 2020

description: Modern accelerators and light sources often require special treatment of the vacuum chamber surface in order to avoid undesirable effects and maximize machine performance. Coatings with Non Evaporable Getter compounds and amorphous Carbon have been extensively tested and used with very effective results since they allow to reduce the secondary electron emission from pipe walls and therefore the relevant beam instability. An electromagnetic characterization of such coatings is therefore fundamental to build a reliable impedance model. We present here a method based on time domain measurements of an electromagnetic wave passing through a tailored waveguide, where the material under test is deposited on a planar slab. This configuration allows an easy measure of samples having a homogeneous coating thickness and a reasonable area, with parameters chosen in order to have a good signal-to-noise ratio, avoiding at the same time problems due to peel-off and blistering during deposition. The study on the electromagnetic response is performed in the frequency range from 0.1 to 0.3 THz, corresponding to the first transverse electric (TE) mode propagation inside the designed waveguide.
description: CERN Yellow Reports: Conference Proceedings, Vol. 9 (2020): Proceedings of the ICFA mini-Workshop on Mitigation of Coherent Beam Instabilities in Particle Accelerators, Zermatt, Switzerland, 23–27 September 2019
A hybrid optical-wireless network for decimetre-level terrestrial positioning
Creators: name: Koelemeij, J. C. J.
name: Dun, H.
name: Diouf, C. E. V.
name: Dierikx, E. F.
name: Janssen, G. J. M.
name: Tiberius, C. C. J. M.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: Global navigation satellite systems (GNSS) are widely used for navigation and time distribution, features indispensable for critical infrastructure such as mobile communication networks, as well as emerging technologies like automated driving and sustainable energy grids. While GNSS can provide centimetre-level precision, GNSS receivers are prone to many-metre errors due to multipath propagation and obstructed view of the sky, which occur especially in urban areas where accurate positioning is needed most. Moreover, the vulnerabilities of GNSS, combined with the lack of a back-up system, pose a severe risk to GNSS-dependent technologies. Here, we demonstrate a terrestrial positioning system which is independent of GNSS and offers superior performance through a constellation of radio transmitters, connected and time-synchronised at the sub-nanosecond level through a fibre-optic Ethernet network. Employing optical and wireless transmission schemes similar to those encountered in mobile communication networks, and exploiting spectrally efficient virtual wideband signals, the detrimental effects of multipath propagation are mitigated, thus enabling robust decimetre-level positioning and sub-nanosecond timing in a multipath-prone outdoor environment. This work provides a glimpse of a future in which telecommunication networks provide not only connectivity, but also GNSS-independent timing and positioning services with unprecedented accuracy and reliability.
description: 38 pages, 9 figures, 3 tables
A central limit theorem associated with a sequence of positive line bundles
Creators: name: Bojnik, Afrim
name: Günyüz, Ozan
Publisher: name: arXiv
Year: 2024
Subjects: subject: Complex Variables (math.CV)
subject: Differential Geometry (math.DG)
subject: Probability (math.PR)
subject: FOS: Mathematics

description: We prove a central limit theorem for smooth linear statistics associated with zero divisors of standard Gaussian holomorphic sections in a sequence of holomorphic line bundles with Hermitian metrics of class $\mathscr{C}^{3}$ over a compact Kähler manifold. In the course of our analysis, we derive first-order asymptotics and upper decay estimates for near and off-diagonal Bergman kernels, respectively. These results are essential for determining the statistical properties of the zeros of random holomorphic sections.
description: Minor revisions, 24 pages
Probing dark energy using anisotropies in the clustering of post-EoR HI distribution
Creators: name: Dash, Chandrachud B. V.
name: Sarkar, Tapomoy Guha
Publisher: name: arXiv
Year: 2024
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We propose an anisotropy quantifier of the HI 21-cm signal traditionally used to clock the astrophysics of the reionization era as a post-reionization dark energy diagnostic. We find that the anisotropy probe can be measured at SNR $\sim 10$ in both auto-correlation and in cross-correlation with the Ly-$α$ forest over a wide $z$ and $k-$range. We propose to use the BAO signature on the anisotropy signal to measure $( H(z), D_A(z))$. Subsequently, we put constraints on a dark energy model involving a negative cosmological constant on top of a quintessence scalar field and find that such a model is consistent with futuristic observations.
description: Submitted
Verzeichnis der Publikationen von Herbert Knittler
Creators: name:  , Redaktion
Publisher: name: Jahrbuch für Geschichte des ländlichen Raumes
Year: 2022

description: Jahrbuch für Geschichte des ländlichen Raumes, Bd. 6 (2009): Zwischen Land und Stadt. Wirtschaftsverflechtungen von ländlichen und städtischen Räumen in Europa 1300–1600
Pacific Urbanisation: Changing Times
Creators: name: Keen, Meg
name: Barbara, Julien
Publisher: name: Canberra, ACT : Coral Bell School of Asia Pacific Affairs, College of Asia and the Pacific, The Australian National University
Year: 2015

description: Throughout the Pacific islands, urban planning and management remain largely neglected. A few Pacific island countries, like PNG, have tried to better manage urban pressures, but implementation of initiatives has been patchy at best; for example, there has been little action on the 2010 PNG National Urbanisation Plan (Jones 2012). While donors recognise urban centres as major drivers of economic growth (ADB 2012), few Pacific leaders have come to terms with the reality of an urban Pacific and the need to manage cities. This In Brief examines some of the key urban challenges in the Pacific islands, and some promising innovations.
Wake fields evaluation for beam collimators and the 60 pc electron beam at the compact ERL at KEK
Creators: name: Tanaka, O.A.
name: Nakamura, N.
name: Obina, T.
name: Tanimoto, Y.
name: Miyajima, T.
name: Shimada, M.
name: Norvell, N.P.
Publisher: name: CERN Yellow Reports: Conference Proceedings
Year: 2020

description: In high-intensity particle accelerators, unwanted transverse and longitudinal wakefields arise when the high- charge particle beam passes through the narrow chambers or locations with small transverse apertures, such as collimator jaws. The transverse wake field may affect the beam emittance and the longitudinal wake field can cause the energy loss and the energy spread. In the present study we investigated the collimator’s impact to the beam performance. In this paper, we have shown numerical, analytical and measurement results on the collimator’s wakefields that will be important for the next step operation. Thus, considering future cERL upgrade to the IR-FEL, a possibility of consequent degradation of the FEL performance should be taken into account. The correspondent power loss was obtained as 13.7 W (81.25 MHz, 5 mA, 2 ps).
description: CERN Yellow Reports: Conference Proceedings, Vol. 9 (2020): Proceedings of the ICFA mini-Workshop on Mitigation of Coherent Beam Instabilities in Particle Accelerators, Zermatt, Switzerland, 23–27 September 2019
Supplementary document for Improving optical coherence of light-emitting diodes by surface plasmons via shallow-etched conic pit array - 6630723.pdf
Creators: name: Zhang, Mingyin
name: TIAN, Zhenhuan
name: Wang, Xuzheng
name: Li, Feng
name: Zhang, Qifan
name: Li, Qiang
name: Li, Yufeng
name: Yun, Feng
Publisher: name: Optica Publishing Group
Year: 2023
Subjects: Uncategorized

description: Supplement 1
Almost periodicity and boundary values of Dirichlet series
Creators: name: Brevig, Ole Fredrik
name: Kouroupis, Athanasios
name: Perfekt, Karl-Mikael
Publisher: name: arXiv
Year: 2024
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: Complex Variables (math.CV)
subject: FOS: Mathematics

description: We employ almost periodicity to establish analogues of the Hardy--Stein identity and the Littlewood--Paley formula for Hardy spaces of Dirichlet series. A construction of Saksman and Seip shows that the limits in this Littlewood--Paley formula cannot be interchanged. We apply this construction to show that the limits in the definition of the mean counting function for Dirichlet series cannot be interchanged. These are essentially statements about the two different kinds of boundary values that we associate with Dirichlet series that converge to a bounded analytic function in a half-plane. The treatment of the mean counting function also involves an investigation of the zero sets and Blaschke products of such Dirichlet series.
description: Minor changes. This paper has been accepted for publication in Transactions of the AMS
Belief functions on lattices
Creators: name: Grabisch, Michel
Publisher: name: arXiv
Year: 2008
Subjects: subject: Discrete Mathematics (cs.DM)
subject: FOS: Computer and information sciences

description: We extend the notion of belief function to the case where the underlying structure is no more the Boolean lattice of subsets of some universal set, but any lattice, which we will endow with a minimal set of properties according to our needs. We show that all classical constructions and definitions (e.g., mass allocation, commonality function, plausibility functions, necessity measures with nested focal elements, possibility distributions, Dempster rule of combination, decomposition w.r.t. simple support functions, etc.) remain valid in this general setting. Moreover, our proof of decomposition of belief functions into simple support functions is much simpler and general than the original one by Shafer.