Journal of African Christian Biography: v. 1, no. 5

A publication of the Dictionary of African Christian Biography with U.S. offices located at the Center for Global Christianity and Mission at Boston University. This issue focuses on: 1. William Wadé Harris, Prophet-Evangelist of West Africa: His Life, Message, Praxis, Heritage, and Legacy. 2. William Wadé Harris. 3. Recent Print and Digital Resources Related to Christianity in Africa

Manipulation of single-photon states encoded in transverse spatial modes: possible and impossible tasks

Controlled generation and manipulation of photon states encoded in their spatial degrees of freedom is a crucial ingredient in many quantum information tasks exploiting higher-than-two dimensional encoding. Here, we prove the impossibility to arbitrarily modify $d$-level state superpositions (qu$d$its) for $d>2$, encoded in the transverse modes of light, with optical components associated to the group of symplectic transforms (Gaussian operations). Surprisingly, we also provide an explicit construction of how non-Gaussian operations acting on mode subspaces do enable to overcome the limit $d=2$. In addition, this set of operations realizes the full SU(3) algebra.Comment: Published in PR

Journal of African Christian Biography: v. 3, no. 1

A publication of the Dictionary of African Christian Biography with U.S. offices located at the Center for Global Christianity and Mission at Boston University. This issue focuses on: 1. “Creole Saga”: The Gambia’s Liberated African Community in the 19th Century: The Stories of J. A. B. Horton, G. C. Nicol, J. R. Maxwell, and J. D. Richards by Asi Florence Mahoney. Introduction by Gabriel Leonard Allen. 2. The Contribution of Daniel William Alexander to the Birth and Growth of Eastern Orthodoxy in East Africa. 3. Biographies by Stephan Hayes and Louise Pirouet. Introduction by Fr. Evangelos Thiani. 4. Recent Print and Digital Resources Related to Christianity in Africa

In Pursuit of Perfection: The Economic Dynamic of Japan As Seen Through the Eyes of Contemporary Confucianism After World War II

Tracing the development of Confucianism in China to contemporary Confucianism in Modern Japan helps us understand her miraculous economy after the ruin of World War II. Deconstructing this socio-cultural phenomenon allows one to weigh the value of Confucianism -- a system of ethics for the individual and the state -- in our modern day times -- especially East Asia

An efficient sampling algorithm for Variational Monte Carlo

We propose a new algorithm for sampling the $N$-body density $|\Psi({\bf R})|^2/\int_{\mathbb{R}^{3N}} |\Psi|^2$ in the Variational Monte Carlo (VMC) framework. This algorithm is based upon a modified Ricci-Ciccotti discretization of the Langevin dynamics in the phase space $({\bf R},{\bf P})$ improved by a Metropolis acceptation/rejection step. We show through some representative numerical examples (Lithium, Fluorine and Copper atoms, and phenol molecule), that this algorithm is superior to the standard sampling algorithm based on the biased random walk (importance sampling).Comment: 23 page

Toward a More Systematic Drafting and Interpreting of the Internal Revenue Code: Expenses, Losses and Bad Debts

upposE that you, as a reasonable man, are asked whether the following two sets of rules mean exactly the same thing. If they do and if you intend to communicate your message as effectively as possible, which of the two sets would you choose to state the organizational rules of your law school? Set 1 A. The financial committee shall be chosen from among the general committee. B. No one shall be a member of both the general and library committees unless he is also on the financial committee. C. No member of the library committee shall be on the financial committee., Set 2 A. The financial committee shall be chosen from among the general committee. B. No member of the general committee shall be on the library committee. We suspect that most readers will have little difficulty in deciding the second question; but even after careful reading of the two sets of rules, they will remain a little puzzled as to whether both sets say the same thing. We further suspect that lawyers waste a great deal of their mental energy by using inadequate and inappropriate intellectual tools to figure out similar logical problems in their everyday work. A symbolic logician could quickly ascertain that the two sets of rules are equivalent and relieve his mind to focus on the more important problem of deciding which is the more appropriate choice

Quasiparticles and phonon satellites in spectral functions of semiconductors and insulators: Cumulants applied to full first principles theory and Fr\"ohlich polaron

The electron-phonon interaction causes thermal and zero-point motion shifts of electron quasiparticle (QP) energies $\epsilon_k(T)$. Other consequences of interactions, visible in angle-resolved photoemission spectroscopy (ARPES) experiments, are broadening of QP peaks and appearance of sidebands, contained in the electron spectral function $A(k,\omega)=-{\Im m}G_R(k,\omega) /\pi$, where $G_R$ is the retarded Green's function. Electronic structure codes (e.g. using density-functional theory) are now available that compute the shifts and start to address broadening and sidebands. Here we consider MgO and LiF, and determine their nonadiabatic Migdal self energy. The spectral function obtained from the Dyson equation makes errors in the weight and energy of the QP peak and the position and weight of the phonon-induced sidebands. Only one phonon satellite appears, with an unphysically large energy difference (larger than the highest phonon energy) with respect to the QP peak. By contrast, the spectral function from a cumulant treatment of the same self energy is physically better, giving a quite accurate QP energy and several satellites approximately spaced by the LO phonon energy. In particular, the positions of the QP peak and first satellite agree closely with those found for the Fr\"ohlich Hamiltonian by Mishchenko $\textit{et al.}$ (2000) using diagrammatic Monte Carlo. We provide a detailed comparison between the first-principles MgO and LiF results and those of the Fr\"ohlich Hamiltonian. Such an analysis applies widely to materials with infra-red active phonons. We also compare the retarded and time-ordered cumulant treatments: they are equivalent for the Fr\"ohlich Hamiltonian, and only slightly differ in first-principles electron-phonon results for wide-band gap materials.Comment: 21 pages, 19 figure

Screening of charged spheroidal colloidal particles

We study the effective screened electrostatic potential created by a spheroidal colloidal particle immersed in an electrolyte, within the mean field approximation, using Poisson--Botzmann equation in its linear and nonlinear forms, and also beyond the mean field by means of Monte Carlo computer simulation. The anisotropic shape of the particle has a strong effect on the screened potential, even at large distances (compared to the Debye length) from it. To quantify this anisotropy effect, we focus our study on the dependence of the potential on the position of the observation point with respect with the orientation of the spheroidal particle. For several different boundary conditions (constant potential, or constant surface charge) we find that, at large distance, the potential is higher in the direction of the large axis of the spheroidal particle

Classical and quantum properties of cylindrically polarized states of light

We investigate theoretical properties of beams of light with non-uniform polarization patterns. Specifically, we determine all possible configurations of cylindrically polarized modes (CPMs) of the electro-magnetic field, calculate their total angular momentum and highlight the subtleties of their structure. Furthermore, a hybrid spatio-polarization description for such modes is introduced and developed. In particular, two independent Poincar\'e spheres have been introduced to represent simultaneously the polarization and spatial degree of freedom of CPMs. Possible mode-to-mode transformations accomplishable with the help of conventional polarization and spatial phase retarders are shown within this representation. Moreover, the importance of these CPMs in the quantum optics domain due to their classical features is highlighted.Comment: 22 pages, 8 figure