Parallel Tempering Simulation of the three-dimensional Edwards-Anderson Model with Compact Asynchronous Multispin Coding on GPU

Monte Carlo simulations of the Ising model play an important role in the field of computational statistical physics, and they have revealed many properties of the model over the past few decades. However, the effect of frustration due to random disorder, in particular the possible spin glass phase, remains a crucial but poorly understood problem. One of the obstacles in the Monte Carlo simulation of random frustrated systems is their long relaxation time making an efficient parallel implementation on state-of-the-art computation platforms highly desirable. The Graphics Processing Unit (GPU) is such a platform that provides an opportunity to significantly enhance the computational performance and thus gain new insight into this problem. In this paper, we present optimization and tuning approaches for the CUDA implementation of the spin glass simulation on GPUs. We discuss the integration of various design alternatives, such as GPU kernel construction with minimal communication, memory tiling, and look-up tables. We present a binary data format, Compact Asynchronous Multispin Coding (CAMSC), which provides an additional $28.4\%$ speedup compared with the traditionally used Asynchronous Multispin Coding (AMSC). Our overall design sustains a performance of 33.5 picoseconds per spin flip attempt for simulating the three-dimensional Edwards-Anderson model with parallel tempering, which significantly improves the performance over existing GPU implementations.Comment: 15 pages, 18 figure

Transliteration of Contact Names and/or Other Data Using an Automated Assistant

Techniques are disclosed herein for transliterating contact names and/or other data from a source language to one or more target languages. The contact names and/or other data are received from a client device (e.g., a feature phone) having an automated assistant. The data in the target language(s) can then be utilized in determining that further input, received from the client device in one of the target language(s), corresponds to certain data in the source language. In one aspect, a method includes receiving, over a network and at one or more remote servers, contact names that are in a source language and that are transmitted from a client device. The method can further include transliterating each of the contact names from the source language to one or more corresponding transliterated contact names in one or more target languages, and mapping each transliterated contact name in the target language(s) to a corresponding contact name in the source language and/or to a corresponding contact entry. The method can further include storing the mapping, along with an identifier of the client device, such as a temporary identifier of the client device. Thereafter, in response to further input received from the client device (e.g., spoken input) in one of the target language(s), the spoken input can be matched to a transliterated contact name, and the mapping utilized to identify a corresponding contact entry and/or contact name in the source language. Thus, techniques disclosed herein can enable a user to create, at a client device, a contact name in a first alphabet (e.g., Latin). The contact name can then be provided to remote server(s), which transliterates the contact name to one or more additional alphabets (e.g., Devanāgarī). Subsequently, the user can provide, at the client device, spoken input that indicates a desire to contact (e.g., call, message, etc.) the contact name, but that references the contact name in the Hindi language (which corresponds to the Devanāgarī alphabet). The spoken input can be provided to one or more of the servers, and the server(s) can match the contact name of the spoken input to a transliteration, of the contact name, that is in the Devanāgarī alphabet. Thus, the contact name can be contacted responsive to the spoken input

On the Classification of Brane Tilings

We present a computationally efficient algorithm that can be used to generate all possible brane tilings. Brane tilings represent the largest class of superconformal theories with known AdS duals in 3+1 and also 2+1 dimensions and have proved useful for describing the physics of both D3 branes and also M2 branes probing Calabi-Yau singularities. This algorithm has been implemented and is used to generate all possible brane tilings with at most 6 superpotential terms, including consistent and inconsistent brane tilings. The collection of inconsistent tilings found in this work form the most comprehensive study of such objects to date.Comment: 33 pages, 12 figures, 15 table

General-relativistic simulations of the formation of a magnetized hybrid star

Strongly magnetized neutron stars are popular candidates for producing detectable electromagnetic and gravitational-wave signals. A rapid density increase in a neutron star core could also trigger the phase transition from hadrons to deconfined quarks and form a hybrid star. This formation process could release a considerable amount of energy in the form of gravitational waves and neutrinos. Hence, the formation of a magnetized hybrid star is an interesting scenario for detecting all these signals. These detections may provide essential probes for the magnetic field and composition of such stars. Thus far, a dynamical study of the formation of a magnetized hybrid star has yet to be realized. Here, we investigate the formation dynamics and the properties of a magnetized hybrid star through dynamical simulations. We find that the maximum values of rest-mass density and magnetic field strength increase slightly and these two quantities are coupled in phase during the formation. We then demonstrate that all microscopic and macroscopic quantities of the resulting hybrid star vary dramatically when the maximum magnetic field strength goes beyond a threshold of $\sim 5 \times 10^{17}$ G but they are insensitive to the magnetic field below this threshold. Specifically, the magnetic deformation makes the rest-mass density drop significantly, suppressing the matter fraction in the mixed phase. Therefore, this work provides a solid support for the magnetic effects on a hybrid star, so it is possible to link observational signals from the star to its magnetic field configuration.Comment: 8 pages, 3 figure