Theory of Resonant Inelastic X-ray Scattering by Collective Magnetic Excitations

I present a tractable theory for the Resonant Inelastic X-ray Scattering (RIXS) spectral function of magnons. The low-energy transition operator is written as a product of local spin operators times fundamental x-ray absorption spectra. This leads to simple selection rules for the magnetic cross section. The scattering cross section linear (quadratic) in spin operators is proportional to the magnetic circular (linear) dichroic absorption. RIXS is a novel tool to measure magnetic quasi particles (magnons) and the incoherent spectral weight, as well as multiple magnons up to very high energy losses, in small samples, thin films and multilayers, complementary to Neutron scattering

FROM SILENCE TO SOUND: CAUSES AND EFFECTS OF THE TALKIES

The era of silent film, though brief in comparison to the history of cinema itself, set a solid foundation for the medium that is beloved by audiences around the world today. However, many stereotypes and preconceived notions surround the lost art that fell from the spotlight at the invention and mass production of sound film a mere thirty-two years after the invention of the motion picture itself. Changing technologies, the adaptations of filmmakers of the period, and the opinions of the general public were all contributing factors in the quick and total transition from silent film to sound film. Through this research, several benefits of silent film became apparent that caused audiences of the late 1920s and early 1930s to be resistant to this change. The works of Alfred Hitchcock and the example of films such as Sunrise: A Song of Two Humans provide case studies for what makes a silent film successful in the eyes of filmmakers and audiences alike. In response to this research and study, a silent short film has been produced using the techniques of classic silent films in the context of film technology today

Kinetic cross coupling between non-conserved and conserved fields in phase field models

We present a phase field model for isothermal transformations of two component alloys that includes Onsager kinetic cross coupling between the non-conserved phase field and the conserved concentration field. We also provide the reduction of the phase field model to the corresponding macroscopic description of the free boundary problem. The reduction is given in a general form. Additionally we use an explicit example of a phase field model and check that the reduced macroscopic description, in the range of its applicability, is in excellent agreement with direct phase field simulations. The relevance of the newly introduced terms to solute trapping is also discussed

A pattern-recognition theory of search in expert problem solving

Understanding how look-ahead search and pattern recognition interact is one of the important research questions in the study of expert problem-solving. This paper examines the implications of the template theory (Gobet & Simon, 1996a), a recent theory of expert memory, on the theory of problem solving in chess. Templates are "chunks" (Chase & Simon, 1973) that have evolved into more complex data structures and that possess slots allowing values to be encoded rapidly. Templates may facilitate search in three ways: (a) by allowing information to be stored into LTM rapidly; (b) by allowing a search in the template space in addition to a search in the move space; and (c) by compensating loss in the "mind's eye" due to interference and decay. A computer model implementing the main ideas of the theory is presented, and simulations of its search behaviour are discussed. The template theory accounts for the slight skill difference in average depth of search found in chess players, as well as for other empirical data

Identifying DsD_s decays at the LHC

In this paper we present two machine learning algorithms to identify $D_s$ mesons from radiative $W$ bosons decays at the LHC. The combined algorithm is able to identify $D_s$ mesons via its hadronic decays with an efficiency of 67% while suppressing a background of quark and gluon jets by a factor of 100.Comment: 10 pages, 6 figure

Onsager approach to 1D solidification problem and its relation to phase field description

We give a general phenomenological description of the steady state 1D front propagation problem in two cases: the solidification of a pure material and the isothermal solidification of two component dilute alloys. The solidification of a pure material is controlled by the heat transport in the bulk and the interface kinetics. The isothermal solidification of two component alloys is controlled by the diffusion in the bulk and the interface kinetics. We find that the condition of positive-definiteness of the symmetric Onsager matrix of interface kinetic coefficients still allows an arbitrary sign of the slope of the velocity-concentration line near the solidus in the alloy problem or of the velocity-temperature line in the case of solidification of a pure material. This result offers a very simple and elegant way to describe the interesting phenomenon of a possible non-single-value behavior of velocity versus concentration which has previously been discussed by different approaches. We also discuss the relation of this Onsager approach to the thin interface limit of the phase field description.Comment: 5 pages, 1 figure, submitted to Physical Review