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Jun 30, 2018
06/18

by
Anna M. Barry; F. Hajir; P. G. Kevrekidis

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In this work, we construct suitable generating functions for vortices of alternating signs in the realm of Bose-Einstein condensates. In addition to the vortex-vortex interaction included in earlier fluid dynamics constructions of such functions, the vortices here precess around the center of the trap. This results in the generating functions of the vortices of positive charge and of negative charge satisfying a modified, so-called, Tkachenko differential equation. From that equation, we...

Topics: Nonlinear Sciences, Quantum Gases, Mathematics, Pattern Formation and Solitons, Mathematical...

Source: http://arxiv.org/abs/1407.7965

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Jun 30, 2018
06/18

by
Bruno Rousseau; François Lapointe; Minh Nguyen; Maxime Biron; Etienne Gaufrès; Saman Choubak; Zheng Han; Vincent Bouchiat; Patrick Desjardins; Michel Côté; Richard Martel

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Herein, intervalley scattering is exploited to account for anomalous antiresonances in the infrared spectra of doped and disordered single layer graphene. We present infrared spectroscopy measurements of graphene grafted with iodophenyl moieties in both reflection microscopy and transmission configurations. Asymmetric transparency windows at energies corresponding to phonon modes near the {\Gamma} and K points are observed, in contrast to the featureless spectrum of pristine graphene. These...

Topics: Mesoscale and Nanoscale Physics, Materials Science, Condensed Matter

Source: http://arxiv.org/abs/1407.8141

3
3.0

Jun 30, 2018
06/18

by
Farhad A. Goodarzi; Daewon Lee; Taeyoung Lee

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We derived a coordinate-free form of equations of motion for a complete model of a quadrotor UAV with a payload which is connected via a flexible cable according to Lagrangian mechanics on a manifold. The flexible cable is modeled as a system of serially-connected links and has been considered in the full dynamic model. A geometric nonlinear control system is presented to exponentially stabilize the position of the quadrotor while aligning the links to the vertical direction below the...

Topics: Mathematics, Optimization and Control

Source: http://arxiv.org/abs/1407.8164

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5.0

Jun 30, 2018
06/18

by
Fernando Cordero; Lavinia Perez-Ostafe

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We study the arbitrage opportunities in the presence of transaction costs in a sequence of binary markets approximating the fractional Black-Scholes model. This approximating sequence was constructed by Sottinen and named fractional binary markets. Since, in the frictionless case, these markets admit arbitrage, we aim to determine the size of the transaction costs needed to eliminate the arbitrage from these models. To gain more insight, we first consider only 1-step trading strategies and we...

Topics: Probability, Mathematics, Quantitative Finance, Pricing of Securities

Source: http://arxiv.org/abs/1407.8068

5
5.0

Jun 30, 2018
06/18

by
Franziska Jahnke; Jochen Koenigsmann

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Admitting a non-trivial $p$-henselian valuation is a weaker assumption on a field than admitting a non-trivial henselian valuation. Unlike henselianity, $p$-henselianity is an elementary property in the language of rings. We are interested in the question when a field admits a non-trivial 0-definable $p$-henselian valuation (in the language of rings). We give a classification of elementary classes of fields in which the canonical $p$-henselian valuation is uniformly 0-definable. We then apply...

Topics: Mathematics, Logic, Commutative Algebra

Source: http://arxiv.org/abs/1407.8156

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3.0

Jun 30, 2018
06/18

by
Frederic Legoll; William Minvielle

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We consider a variance reduction approach for the stochastic homogenization of divergence form linear elliptic problems. Although the exact homogenized coefficients are deterministic, their practical approximations are random. We introduce a control variate technique to reduce the variance of the computed approximations of the homogenized coefficients. Our approach is based on a surrogate model inspired by a defect-type theory, where a perfect periodic material is perturbed by rare defects....

Topics: Mathematics, Numerical Analysis, Probability

Source: http://arxiv.org/abs/1407.8029

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5.0

Jun 30, 2018
06/18

by
Friedrich Knop; Bernhard Krötz; Eitan Sayag; Henrik Schlichtkrull

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We apply the local structure theorem and the polar decomposition to a real spherical space Z=G/H and control the volume growth on Z. We define the Harish-Chandra Schwartz space on Z. We give a geometric criterion to ensure $L^p$-integrability of matrix coefficients on Z.

Topics: Mathematics, Representation Theory

Source: http://arxiv.org/abs/1407.8006

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7.0

Jun 30, 2018
06/18

by
Leandro Cagliero; Fernando Szechtman

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Let ${\mathfrak g}$ be a finite dimensional Lie algebra over a field of characteristic 0, with solvable radical ${\mathfrak r}$ and nilpotent radical ${\mathfrak n}=[{\mathfrak g},{\mathfrak r}]$. Given a finite dimensional ${\mathfrak g}$-module $U$, its nilpotency series $ 0\subset U({\mathfrak n}^1)\subset\cdots\subset U({\mathfrak n}^m)=U$ is defined so that $U({\mathfrak n}^1)$ is the 0-weight space of ${\mathfrak n}$ in $U$, $U({\mathfrak n}^2)/U({\mathfrak n}^1)$ is the 0-weight space of...

Topics: Mathematics, Representation Theory

Source: http://arxiv.org/abs/1407.8125

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4.0

Jun 30, 2018
06/18

by
M. Zuppardo; J. P. Santos; G. De Chiara; M. Paternostro; F. L. Semiao; G. M. Palma

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We describe an apparatus designed to make non-demolition measurements on a Bose-Einstein condensate (BEC) trapped in a double-well optical cavity. This apparatus contains, as well as the bosonic gas and the trap, an optical cavity. We show how the interaction between the light and the atoms, under appropriate conditions, can allow for a weakly disturbing yet highly precise measurement of the population imbalance between the two wells and its variance. We show that the setting is well suited for...

Topics: Quantum Physics, Quantum Gases, Condensed Matter

Source: http://arxiv.org/abs/1407.8077

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4.0

Jun 30, 2018
06/18

by
Taras Verkholyak; Jozef Strecka; Frederic Mila; Kai P. Schmidt

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Exact ground states of a spin-1/2 Ising-Heisenberg model on the Shastry-Sutherland lattice with Heisenberg intra-dimer and Ising inter-dimer couplings are found by two independent rigorous procedures. The first method uses a unitary transformation to establish a mapping correspondence with an effective classical spin model, while the second method relies on the derivation of an effective hard-core boson model by continuous unitary transformations. Both methods lead to equivalent effective...

Topics: Statistical Mechanics, Condensed Matter

Source: http://arxiv.org/abs/1407.8229

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Jun 30, 2018
06/18

by
Yuancheng Fan; Fuli Zhang; Qian Zhao; Zeyong Wei; Hongqiang Li

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Coherent perfect absorber (CPA) was proposed as the time-reversed counterpart to laser: a resonator containing lossy medium instead of gain medium can absorb the coherent optical fields completely. Here, we exploit a monolayer graphene to realize the CPA in a non-resonant manner. It is found that quasi-CPA point exists in the terahertz regime for suspending monolayer graphene, and the CPA can be implemented with the assistant of proper phase modulation among two incident beams at the quasi-CPA...

Topics: Physics, Mesoscale and Nanoscale Physics, Optics, Materials Science, Condensed Matter

Source: http://arxiv.org/abs/1407.7961

3
3.0

Jun 30, 2018
06/18

by
Yuchen Peng; Frank Gaitan

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Successful implementation of a fault-tolerant quantum computation on a system of qubits places severe demands on the hardware used to control the many-qubit state. It is known that an accuracy threshold $P_{a}$ exists for any quantum gate that is to be used in such a computation. Specifically, the error probability $P_{e}$ for such a gate must fall below the accuracy threshold: $P_{e} < P_{a}$. Estimates of $P_{a}$ vary widely, though $P_{a}\sim 10^{-4}$ has emerged as a challenging target...

Topics: Quantum Physics, Mesoscale and Nanoscale Physics, Condensed Matter

Source: http://arxiv.org/abs/1407.8074