Asymptotic Solutions of the Phase Space Schrodinger Equation: Anisotropic Gaussian Approximation

We consider the singular semiclassical initial value problem for the phase space Schrodinger equation. We approximate semiclassical quantum evolution in phase space by analyzing initial states as superpositions of Gaussian wave packets and applying individually semiclassical anisotropic Gaussian wave packet dynamics, which is based on the the nearby orbit approximation; we accordingly construct a semiclassical approximation of the phase space propagator, semiclassical wave packet propagator, which admits WKBM semiclassical states as initial data. By the semiclassical propagator we construct asymptotic solutions of the phase space Schrodinger equation, noting the connection of this construction to the initial value repsresentations for the Schrodinger equation

Characteristics of reaction-diffusion on scale-free networks

We examine some characteristic properties of reaction-diffusion processes of the A+A->0 type on scale-free networks. Due to the inhomogeneity of the structure of the substrate, as compared to usual lattices, we focus on the characteristics of the nodes where the annihilations occur. We show that at early times the majority of these events take place on low-connectivity nodes, while as time advances the process moves towards the high-connectivity nodes, the so-called hubs. This pattern remarkably accelerates the annihilation of the particles, and it is in agreement with earlier predictions that the rates of reaction-diffusion processes on scale-free networks are much faster than the equivalent ones on lattice systems

The Protea Peace Parade

New editorial associate, Dr. Panos D. Bardis of Toledo U niversity, con­ tributed this poem after a visit to South Africa

Evolution of human needs in changing civilizations

[Δε διατίθεται περίληψη / no abstract available]The theory presented in this study is that, as scienceand technology advance and the resulting affluencegenerates higher levels of satisfaction for man’sphysiological drives, our emphasis on sociopsychologicalneeds becomes greater and greater. The dataemployed to test this theory were of two types: one,macroanalytical or historical, and two, microanalyticalor semihistorical, the latter being the problemsand needs of New York’s «neediest» families. Atleast the data included here do support the theory.The numerous implications of these findings areobvious. Below are a few of them:1. We need a standardized and more precise andsystematic nomenclature of human needs in orderto study them more fruitfully.2. Our increasing affluence necessitates further researchinto the psychology and sociology of leisuretime.3. More meaningful education in this sector is alsonecessary.4. We must explore the exact relationship betweenfrustration and violence.5. Social planning in these areas is something thatcan no longer be postponed with impunity.6. The developing economies of the Third Worldwill generate new sociopsychological needs which,unless appropriate measures are taken, may resultin social unrest and even violence.7. Finally, the utopian plans of those who conceiveof purely economic solutions as sufficient panaceasare simplistic and ludicrous, as they reveal theiradvocates’ inability to understand the nature ofboth our physiological and sociopsychological needs.Unfortunately, although physical satiety is ofteneasy to achieve, there is no answer, for instance, tothis question: When does a man have enough power?For man’s sociopsychological needs are insatiable,boundless, unfathomable

Can one count the shape of a drum?

Sequences of nodal counts store information on the geometry (metric) of the domain where the wave equation is considered. To demonstrate this statement, we consider the eigenfunctions of the Laplace-Beltrami operator on surfaces of revolution. Arranging the wave functions by increasing values of the eigenvalues, and counting the number of their nodal domains, we obtain the nodal sequence whose properties we study. This sequence is expressed as a trace formula, which consists of a smooth (Weyl-like) part which depends on global geometrical parameters, and a fluctuating part which involves the classical periodic orbits on the torus and their actions (lengths). The geometrical content of the nodal sequence is thus explicitly revealed.Comment: 4 pages, 1 figur

ESTIMATION OF EXPORT DEMAND FUNCTIONS FOR U.S. WHEAT

Export demand functions for U.S. wheat were estimated for five world regions. Estimates of the effects of income, price, and nonprice variables on U.S. wheat exports were obtained using various econometric procedures. The major finding of the paper indicates that exchange rate changes have had a substantial impact on U.S. wheat exports. This result, conditioned on the aggregative nature of the study, supports the belief expressed by some researchers in recent years.Demand and Price Analysis, International Relations/Trade,

Simple proof of fault tolerance in the graph-state model

We consider the problem of fault tolerance in the graph-state model of quantum computation. Using the notion of composable simulations, we provide a simple proof for the existence of an accuracy threshold for graph-state computation by invoking the threshold theorem derived for quantum circuit computation. Lower bounds for the threshold in the graph-state model are then obtained from known bounds in the circuit model under the same noise process.Comment: 6 pages, 2 figures, REVTeX4. (v4): Minor revisions and new title; published versio