Hasil untuk "Periodicals"

M. Bukov, L. D'Alessio, A. Polkovnikov

We give a general overview of the high-frequency regime in periodically driven systems and identify three distinct classes of driving protocols in which the infinite-frequency Floquet Hamiltonian is not equal to the time-averaged Hamiltonian. These classes cover systems, such as the Kapitza pendulum, the Harper–Hofstadter model of neutral atoms in a magnetic field, the Haldane Floquet Chern insulator and others. In all setups considered, we discuss both the infinite-frequency limit and the leading finite-frequency corrections to the Floquet Hamiltonian. We provide a short overview of Floquet theory focusing on the gauge structure associated with the choice of stroboscopic frame and the differences between stroboscopic and non-stroboscopic dynamics. In the latter case, one has to work with dressed operators representing observables and a dressed density matrix. We also comment on the application of Floquet Theory to systems described by static Hamiltonians with well-separated energy scales and, in particular, discuss parallels between the inverse-frequency expansion and the Schrieffer–Wolff transformation extending the latter to driven systems.

A. Kamenev

The physics of non-equilibrium many-body systems is a rapidly expanding area of theoretical physics. Traditionally employed in laser physics and superconducting kinetics, these techniques have more recently found applications in the dynamics of cold atomic gases, mesoscopic and nano-mechanical systems, and quantum computation. This book provides a detailed presentation of modern non-equilibrium field-theoretical methods, applied to examples ranging from biophysics to the kinetics of superfluids and superconductors. A highly pedagogical and self-contained approach is adopted within the text, making it ideal as a reference for graduate students and researchers in condensed matter physics. In this Second Edition, the text has been substantially updated to include recent developments in the field such as driven-dissipative quantum systems, kinetics of fermions with Berry curvature, and Floquet kinetics of periodically driven systems, among many other important new topics. Problems have been added throughout, structured as compact guided research projects that encourage independent exploration.

J. McCormack

Collective Memory examines the difficult transmission of memory in France of the Algerian war of independence (1954-62). Emphasizing the current lack of transmission of memories of this war through a detailed case study of three crucial vectors of memory: the teaching of school history, coverage in the media, and discussion in the family, author McCormack argues that lack of transmission of memories is feeding into contemporary racism and exclusion in France. Collective Memory draws extensively on interviews with historians, teachers, and pupils as well as secondary sources and media analysis. McCormack proposes that a greater 'work of memory' needs to be undertaken if France is to overcome the division in French society that stems from the war. There has been little reconciliation of divisive group memories, a situation that leaves many individuals without a voice on this important subject. 'Memory battles' dominate discussion of the topic as many issues periodically flare up and cannot yet be overcome.

V. Khemani, A. Lazarides, R. Moessner et al.

Clean and interacting periodically driven systems are believed to exhibit a single, trivial "infinite-temperature" Floquet-ergodic phase. In contrast, here we show that their disordered Floquet many-body localized counterparts can exhibit distinct ordered phases delineated by sharp transitions. Some of these are analogs of equilibrium states with broken symmetries and topological order, while others-genuinely new to the Floquet problem-are characterized by order and nontrivial periodic dynamics. We illustrate these ideas in driven spin chains with Ising symmetry.

R. Isbell

The Australian Soil Classification provides a framework for organising knowledge about Australian soils by allocating soils to classes via a key. Since its publication in 1996, this book has been widely adopted and formally endorsed as the official national system. It has provided a means of communication among scientists and land managers and has proven to be of particular value in land resource survey and research programs, environmental studies and education. Classification is a basic requirement of all science and needs to be periodically revised as knowledge increases. This third edition of The Australian Soil Classification includes updates from a working group of the National Committee on Soil and Terrain (NCST). The main change in this edition accommodates new knowledge and understanding of the significance, nature, distribution and refined testing for soils comprising deep sands, leading to the inclusion of a new Order, the Arenosols. The introduction of the Arenosols Order led to a review and changes to Calcarosols, Tenosols and Rudosols. The Australian Soil Classification is Volume 4 in the Australian Soil and Land Survey Handbooks Series.

A. Maritim, R. Sanders, J. Watkins

Zhilin Yang, R. Peterson

S. Manolagas

B. Bloom

Paul A. Gompers

G. Allaire

D. Morens, G. Folkers, A. Fauci

Infectious diseases have for centuries ranked with wars and famine as major challenges to human progress and survival. They remain among the leading causes of death and disability worldwide. Against a constant background of established infections, epidemics of new and old infectious diseases periodically emerge, greatly magnifying the global burden of infections. Studies of these emerging infections reveal the evolutionary properties of pathogenic microorganisms and the dynamic relationships between microorganisms, their hosts and the environment.

P. Holland

Ossama Younis, S. Fahmy

O. S. Salawu

M. Whitfield, G. Sherlock, A. Saldanha et al.

T. Sadler

M. Parrinello, A. Rahman

J. Hagenauer

Wei Mao, Miaomiao Liu, M. Salzmann

Human motion prediction aims to forecast future human poses given a past motion. Whether based on recurrent or feed-forward neural networks, existing methods fail to model the observation that human motion tends to repeat itself, even for complex sports actions and cooking activities. Here, we introduce an attention-based feed-forward network that explicitly leverages this observation. In particular, instead of modeling frame-wise attention via pose similarity, we propose to extract motion attention to capture the similarity between the current motion context and the historical motion sub-sequences. Aggregating the relevant past motions and processing the result with a graph convolutional network allows us to effectively exploit motion patterns from the long-term history to predict the future poses. Our experiments on Human3.6M, AMASS and 3DPW evidence the benefits of our approach for both periodical and non-periodical actions. Thanks to our attention model, it yields state-of-the-art results on all three datasets. Our code is available at this https URL.