Dynamical electron transport through a nanoelectromechanical wire in a magnetic field

We investigate dynamical transport properties of interacting electrons moving in a vibrating nanoelectromechanical wire in a magnetic field. We have built an exactly solvable model in which electric current and mechanical oscillation are treated fully quantum mechanically on an equal footing. Quantum mechanically fluctuating Aharonov-Bohm phases obtained by the electrons cause nontrivial contribution to mechanical vibration and electrical conduction of the wire. We demonstrate our theory by calculating the admittance of the wire which are influenced by the multiple interplay between the mechanical and the electrical energy scales, magnetic field strength, and the electron-electron interaction

Radiation content of Conformally flat initial data

We study the radiation of energy and linear momentum emitted to infinity by the headon collision of binary black holes, starting from rest at a finite initial separation, in the extreme mass ratio limit. For these configurations we identify the radiation produced by the initially conformally flat choice of the three geometry. This identification suggests that the radiated energy and momentum of headon collisions will not be dominated by the details of the initial data for evolution of holes from initial proper separations $L_0\geq7M$. For non-headon orbits, where the amount of radiation is orders of magnitude larger, the conformally flat initial data may provide a relative even better approximation.Comment: 4 pages, 4 figure

Identifying Olivine Composition in Tyrrhena Terra, Mars, Using Orbital Mid-Infrared Data

Magnificent rock / Crater floors of melted Mars / Hold the olivine

Non-linear regression models for Approximate Bayesian Computation

Approximate Bayesian inference on the basis of summary statistics is well-suited to complex problems for which the likelihood is either mathematically or computationally intractable. However the methods that use rejection suffer from the curse of dimensionality when the number of summary statistics is increased. Here we propose a machine-learning approach to the estimation of the posterior density by introducing two innovations. The new method fits a nonlinear conditional heteroscedastic regression of the parameter on the summary statistics, and then adaptively improves estimation using importance sampling. The new algorithm is compared to the state-of-the-art approximate Bayesian methods, and achieves considerable reduction of the computational burden in two examples of inference in statistical genetics and in a queueing model.Comment: 4 figures; version 3 minor changes; to appear in Statistics and Computin

Characterizing the Aqueous Geochemical History at Tyrrhena Terra, Mars

Tyrrhena Terra is an intriguing region of Mars extending from the southern part of Isidis Basin at the Libya Montes southward to Hellas Basin. Noachian and Hesperian basement rocks are covered by Syrtis lavas, especially in the northwestern part of Tyrrhena Terra and the surface is carved by craters and fluvial features. The central region is marked by the craters Jarry-Desloges, Owen, and Briault, and contains abundant Fe/Mg-rich phyllosilicates and olivine-bearing outcrops in Noachian-Hesperian terrain [1,2]. Many of the phyllosilicates in this region are located in crater ejecta and in central crater mounds, consistent with uplift of ancient materials, but some are present in dissected terrains. We are investigating the mineralogy and geology of this region through a coordinated study using TES, THEMIS, CRISM multispectral strips, CTX and HRSC imagery, and HRSC digital elevation models at a regional scale, as well as CRISM targeted images and HiRISE views of the surface at a closer scale. The phyllosilicate spectra across the central Tyrrhena Terra region (see attached figure) are most consistent with chlorite, Fe/Mg-smectite, and mixed smectite-chlorite. A few hydrated silica and zeolite outcrops are also present. This mineralogy is consistent with higher temperature processes than the primarily Fe/Mg-smectite and carbonate spectra observed in the Libya Montes region [3,4]. A few sites towards the east of our study site contain more Fe/Mg-smectite than chlorite and additional hydrated phases including sulfates, which likely represent a different formation environment. Ongoing investigations of the targeted CRISM images at the eastern part of this area are characterizing the stratigraphy of these aqueous units and their association with higher temperature units towards the west and smectite-carbonate units towards the north

Technology-Supported Storytelling (TSST) Strategy in Virtual World for Multicultural Education

Learning culture through stories is an effective way for multicultural education, since stories are one of the most powerful and personal ways that we learn about the world. Storytelling, the process of telling stories, is a form of communication and a universal expression of culture. With the development of technology, storytelling emerges out of diverse ways. This study explores the storytelling in virtual worlds for multicultural education, and devises a Technology-Supported storytelling (TSST) strategy by examining and considering the characteristics of virtual worlds which could be incorporated into the storytelling, and then uses this strategy to teach Korean culture to students with different culture background. With this innovative TSST strategy in virtual world, this study expects to provide a guide to practice for teaching multicultural in digital era

The ^4He trimer as an Efimov system

We review the results obtained in the last four decades which demonstrate the Efimov nature of the $^4$He three-atomic system.Comment: Review article for a special issue of the Few-Body Systems journal devoted to Efimov physic