Angular reduction in multiparticle matrix elements

A general method for the reduction of coupled spherical harmonic products is presented. When the total angular coupling is zero, the reduction leads to an explicitly real expression in the scalar products within the unit vector arguments of the spherical harmonics. For non-scalar couplings, the reduction gives Cartesian tensor forms for the spherical harmonic products, with tensors built from the physical vectors in the original expression. The reduction for arbitrary couplings is given in closed form, making it amenable to symbolic manipulation on a computer. The final expressions do not depend on a special choice of coordinate axes, nor do they contain azimuthal quantum number summations, nor do they have complex tensor terms for couplings to a scalar. Consequently, they are easily interpretable from the properties of the physical vectors they contain.Comment: This version contains added comments and typographical corrections to the original article. Now 27 pages, 0 figure

Quantum Walks of SU(2)_k Anyons on a Ladder

We study the effects of braiding interactions on single anyon dynamics using a quantum walk model on a quasi-1-dimensional ladder filled with stationary anyons. The model includes loss of information of the coin and nonlocal fusion degrees of freedom on every second time step, such that the entanglement between the position states and the exponentially growing auxiliary degrees of freedom is lost. The computational complexity of numerical calculations reduces drastically from the fully coherent anyonic quantum walk model, allowing for relatively long simulations for anyons which are spin-1/2 irreps of SU(2)_k Chern-Simons theory. We find that for Abelian anyons, the walk retains the ballistic spreading velocity just like particles with trivial braiding statistics. For non-Abelian anyons, the numerical results indicate that the spreading velocity is linearly dependent on the number of time steps. By approximating the Kraus generators of the time evolution map by circulant matrices, it is shown that the spatial probability distribution for the k=2 walk, corresponding to Ising model anyons, is equal to the classical unbiased random walk distribution.Comment: 12 pages, 4 figure

Homegrown Terror: Benedict Arnold and the Burning of New London

Benedict Arnold was a man who could have been a “founding father” of America, but instead became a national villain. His brutal attack on Connecticut epitomizes this transformation: the moment where an abstract idea of betrayal completes its evolution to the slaughter and destruction of his neighbors and their homes. Focusing on this significant but unfortunately forgotten incident addresses some of the major challenges of any discussion about this complex and confusing American figure. It also directly links Arnold’s story with the stories of his friends and colleagues, something that has never been done before. The combination of these two approaches puts the focus on Arnold’s effects rather than his motives, and on the victims rather than the attacker. Moreover, it reframes his “treason” as “homegrown terror,” a term that resonates with modern readers and whose definition echoes the 18th century word “parricide,” used by many contemporaries to describe Arnold’s actions

Voice of the Moment: Henry Miller’s Paris Notebooks and the Problem of Autobiographical Fiction

In 2010 Yale's Beinecke Rare Book and Manuscript Library acquired Henry Miller's three "Paris Notebooks," which have been in private hands and read by only a few scholars over the past ninety years. They are a working writer's hodge-podge of undated diary entries, descriptions of places and people, lists, letters, rough drafts, and unpublished pieces. After close examination of the manuscripts, I assessed that these pages offer important insights, and I am writing a critical biography to expose their impact. The notebooks shed particular light on Miller's process, which seems far less "inspired" or "prophetic" and much more "workmanlike" than previously imagined. The first published result of this process, Tropic of Cancer, inspired generations of authors to write loosely autobiographical fiction, but also created a new problem when discussing these works. Many critics and even biographers conflate Henry Miller the person with the narrator or character of "Henry" in Tropic of Cancer and his other books. This is not a problem confined to scholarship on one author. Our literary culture continues to misunderstand poets and novelists who write in voices we imagine to be their own, whose "characters" speaking in On the Road or "Lady Lazarus" seem to be the same person as Jack Kerouac or Sylvia Plath, when in fact each is a persona, a voice of the moment

Yours Truly: The Practice of Writing Letters

Is letter-writing dead? Has the internet killed it? In “Yours Truly,” Eric D. Lehman finds that while the style may be changing, the form of correspondence known as a letter is alive and well. Just as a conversation is more than delivering news, expressing your thoughts to a reader fully and completely, whether on paper or on an electronic screen, transcends the mere message in both its intention and effect. And even though the resulting letters are personal documents usually intended for one reader, they can be considered literature just as readily as an autobiography or personal essay

Punctuated Equilibrium in Software Evolution

The approach based on paradigm of self-organized criticality proposed for experimental investigation and theoretical modelling of software evolution. The dynamics of modifications studied for three free, open source programs Mozilla, Free-BSD and Emacs using the data from version control systems. Scaling laws typical for the self-organization criticality found. The model of software evolution presenting the natural selection principle is proposed. The results of numerical and analytical investigation of the model are presented. They are in a good agreement with the data collected for the real-world software.Comment: 4 pages, LaTeX, 2 Postscript figure

Importance of Baryon-Baryon Coupling in Hypernuclei

The $\Lambda N - \Sigma N$ coupling in $\Lambda$--hypernuclei and $\Lambda \Lambda - \Xi N$ coupling in $\Lambda \Lambda$--hypernuclei produce novel physics not observed in the conventional, nonstrange sector. Effects of $\Lambda \leftrightarrow \Sigma$ conversion in $^3_{\Lambda}$H are reviewed. The role of $\Lambda N - \Sigma N$ coupling suppression in the $A=4,5$ $\Lambda$--hypernuclei due to Pauli blocking is highlighted, and the implications for the structure of $^{10}_{\;\, \Lambda}$B are explored. Suppression of $\Lambda \Lambda - \Xi N$ conversion in $^{\;\;\, 6}_{\Lambda \Lambda}$He is hypothesized as the reason that the $$ matrix element is small. Measurement of $^{\;\;\, 4}_{\Lambda \Lambda}$H is proposed to investigate the full $\Lambda \Lambda - \Xi N$ interaction. The implication for $\Lambda \Lambda$ analog states is discussed.Comment: 17 pages LATEX, 1 figure uuencoded postscrip

YouTube Video Project: A Cool Way to Learn Communication Ethics

The millennial generation embraces new technologies as a natural way of accessing and exchanging information, staying connected, and having fun. YouTube, a video-sharing site that allows users to upload, view, and share video clips, is among the latest “cool” technologies for enjoying quick laughs, employing a wide variety of corporate activities, and also communicating relevant, engaging instructional content for today’s students. This article describes a YouTube video class project that is a natural fit with today’s students because it involves cutting-edge social media while addressing a critical component of professional development—communication ethics. This project encourages critical thinking, creativity, and applied learning in a team environment using a “cool” new media tool