Class of exact memory-kernel master equations

A well-known situation in which a non-Markovian dynamics of an open quantum system $S$ arises is when this is coherently coupled to an auxiliary system $M$ in contact with a Markovian bath. In such cases, while the joint dynamics of $S$-$M$ is Markovian and obeys a standard (bipartite) Lindblad-type master equation (ME), this is in general not true for the reduced dynamics of $S$. Furthermore, there are several instances (\eg the dissipative Jaynes-Cummings model) in which a {\it closed} ME for the $S$'s state {\it cannot} even be worked out. Here, we find a class of bipartite Lindblad-type MEs such that the reduced ME of $S$ can be derived exactly and in a closed form for any initial product state of $S$-$M$. We provide a detailed microscopic derivation of our result in terms of a mapping between two collision modelsComment: 9 pages, 1 figur

Perovskite Manganites Hosting Versatile Multiferroic Phases with Symmetric and Antisymmetric Exchange Strictions

Complete magnetoelectric (ME) phase diagrams of orthorhombic $R$MnO$_{3}$ with and without magnetic moments on the $R$ ions have been established. Three kinds of multiferroic ground states, the $ab$-cycloidal, the $bc$-cycloidal, and the collinear $E$-type phases, have been identified by the distinct ME responses. The electric polarization of the $E$-type phase dominated by the symmetric spin exchange ($bm{S}_{i} cdot bm{S}_{j}$) is more than 10 times as large as that of the $bc$-cycloidal phase dominated by the antisymmetric one ($bm{S}_{i} times bm{S}_{j}$), and the ME response is enhanced near the bicritical phase boundary between these multiferroic phases of different origins. These findings will provide an important clue for the development of the magnetically induced multiferroics.Comment: 5 pages, 3 figure

The cycloauration of pyridine-2-thiocarboxamide ligands

Reactions of H[AuCl₄] with N-substituted 2-pyridine thiocarboxamide ligands 2-(C₅H₄N)C(S)NHR (R= p-C₆H₄Me, CH₂Ph, Me, p-C₆H₄OMe) gave cycloaurated derivatives {(C₅H₄N)C(S)NR}AuCl₂, with the ligand bonded as the thiol tautomer through the deprotonated SH group and the pyridine N atom to give a five-membered metallacyclic ring. The X-ray structure determination of the R = CH₂Ph derivative shows a square-planar gold(III) complex that dimerises in the solid state by weak Au...S intermolecular interactions. In contrast, in the reaction of H[AuCl₄] with 2-(C₅H₄N)C(S)NHR where R = 2-pyridyl, the ligand was oxidised to give a 1,2,4-thiadiazolo[2,3-a]pyridinium heterocyclic ring that was crystallographically characterised

Black Police Associations and the police occupational culture

In recent years, Black Police Associations (BPAs) have become key forces of change within the police service, involved in minority ethnic recruitment and retention initiatives, working closely with senior management, and also serving as mechanisms of support minority ethnic constabulary members and recruits. Most police services in England and Wales now have an officially recognised BPA, making it essential to consider the effect these groups have on the police occupational culture. Using data from our recent research project on BPAs, we explore issues such as the decreasing importance of rank and grading in the police culture; whether a parallel, ‘black’ occupational culture is emerging alongside the traditional ‘white’ one; the indirect influence BPAs have had as part of a wider process of change and the interplay between changing individuals and changing the institution as a whole

ACL and God’s Call to Librarianship

Many people have asked me how, as a librarian in a secular institution, I became so involved in ACL. I have been at Auburn University Libraries since 1978, but before that was at a Christian liberal arts college, now defunct. ACL has been part of my life since the early 70’s and, of all the professional organizations to which I have belonged, it is the one that has had the greatest effect on me personally

Makvala Kasrashvili, soprano and Liya Mogilevskaya, piano, March 28, 1988

This is the concert program of the Makvala Kasrashvili, soprano and Liya Mogilevskaya, piano performance on Monday, March 28, 1988 at 8:00 p.m., at the Concert Hall, 855 Commonwealth Avenue. Works performed were Not a Word, My Friend by Pyotr Ilyich Tchaikovsky, Don't Ask! by P. I. Tchaikovsky, It Was Early Spring by P. I. Tchaikovsky, So What is There to Do? by P. I. Tchaikovsky, Tell Me of What, In the Shadow of the Branches by P. I. Tchaikovsky, To My Sorrow I Fell in Love by Sergei Rachmaninoff, A Dream by S. Rachmaninoff, A Passage from Musset by S. Rachmaninoff, The Lilac by S. Rachmaninoff, Everything Has Been Taken from Me by S. Rachmaninoff, Oh, I'm Sorrowful by S. Rachmaninoff, I Await You by S. Rachmaninoff, Where are you, little star? by Modest Mussorgsky, Hopak by M. Mussorgsky, Seven Spanish Folk Songs by Manuel de Falla, Mi chiamano Mimi from "La Bohème" by Giacomo Puccini, and Voi lo sapete from "Cavalleria Rusticana" by Pietro Mascagni. Digitization for Boston University Concert Programs was supported by the Boston University Humanities Library Endowed Fund

Reply to Duncan Pritchard and John Campbell

An epistemological how-possible question asks how knowledge, or knowledge of some specific kind, is possible. The main contention of Duncan Pritchard‟s stimulating comments is that what I call „explanatory minimalism‟ appears to offer us just what we are seeking when we ask such a question. This looks like a problem for me given that I defend a version of explanatory anti-minimalism. Pritchard outlines a version of minimalism inspired by the writings of John McDowell and does not find it obvious that this position is lacking in any relevant respect. Nor do I. My minimalism is moderate rather than extreme but Pritchard‟s objections to anti-minimalism are objections to extreme anti-minimalism. Indeed, his comments do not seem to me to have any direct bearing on what I take to be the fundamental disagreement between minimalism and anti-minimalism

Alas, Alack! Revisited

In Gargantua and Pantagruel, Book 4, Chapter XVIII through XXI, Pantagruel and his men are facing a dreadful storm at sea. One of the sailors, Panurge, is convinced of impeding death and spends all four chapter blubbering. While he lets loose with a few boo-hoo-hoo s and a few well-placed woe is me! woe, woe! s and the like, most of interjections are highly original, packed with logological curiosities

A note on the cone of mobile curves

S. Boucksom, J.-P. Demailly, M. Paun and Th. Peternell proved that the cone of mobile curves ME(X) of a projective complex manifold X is dual to the cone generated by classes of effective divisors and conjectured an extension of this duality in the Kaehler set-up. We show that their conjecture implies that ME(X) coincides with the cone of integer classes represented by closed positive smooth (n-1,n-1)-forms. Without assuming the validity of the conjecture we prove that this equality of cones still holds at the level of degree functions