Krylov-space approach to the equilibrium and the nonequilibrium single-particle Green's function

The zero-temperature single-particle Green's function of correlated fermion models with moderately large Hilbert-space dimensions can be calculated by means of Krylov-space techniques. The conventional Lanczos approach consists of finding the ground state in a first step, followed by an approximation for the resolvent of the Hamiltonian in a second step. We analyze the character of this approximation and discuss a numerically exact variant of the Lanczos method which is formulated in the time domain. This method is extended to get the nonequilibrium single-particle Green's function defined on the Keldysh-Matsubara contour in the complex time plane. The proposed method will be important as an exact-diagonalization solver in the context of self-consistent or variational cluster-embedding schemes. For the recently developed nonequilibrium cluster-perturbation theory, we discuss the efficient implementation and demonstrate the feasibility of the Krylov-based solver. The dissipation of a strong local magnetic excitation into a non-interacting bath is considered as an example for applications.Comment: 20 pages, 5 figures, v2 with minor corrections, JPCM in pres

Bis(4,6-diaminopyrimidin-2-yl) disulfide dimethyl sufoxide disolvate

The title compound, C8H10N8S2·2C2H6SO, was obtained unintentionally during an attempt to prepare a thiol-ate derivative of trimethyl-tin. The complete disulfide mol-ecule is generated by twofold rotation symmetry and the C - S - S - C torsion angle around the S - S bond is -85.70 (10)°. The mol-ecules are connected via N - H⋯N hydrogen bonds into strongly corrugated layers parallel to (001), generating an R 2 2(8) motif. The solvent mol-ecule, which exhibits minor disorder of its S atom [site occupancies = 0.9591 (18) and 0.0409 (18)], is linked to this layer via a pair of N - H⋯O inter-actions

Investigation of the structure and catalytic activity in olefin cyclopropanation of neutral and cationic dicopper complexes of 3,5-bis(pyridinylimino)benzoic acid.

Three neutral and one cationic copper(I) complexes with 3,5-bis(pyridinylimino)benzoic acid are synthesized and characterized in solution and in the solid state by a variety of spectroscopic techniques and X-ray crystallography. The compounds are tested for their catalytic activity in olefin cyclopropanation reactions by means of ethyl diazoacetate decomposition and prove to be moderately active with the ionic one being the most active and the most promising since for cyclohexene it reveals a considerable diastereoselectivity and a 90:10 exo:endo ratio of the final product

An Analysis of the Musical Gestures in Osvaldo Golijov’s The Dreams and Prayers of Isaac the Blind and their Relationship to the Kabbalah Sefirot

Osvlado Golijov’s The Dreams and Prayers of Isaac the Blind, scored for klezmer clarinet and string quartet, remains one of his most influential works since its premier in 1994. Inspiration for the work came from the writings of Rabbi Isaac the Blind, a prominent 13th century figurehead in the branch of Jewish mysticism known as Kabbalah. In Kabbalah, symbols known as the sefirot are emanations of creation and the key to unlocking the divine secrets of the God-head. The analysis presented in this document combines musical gesture theory with Kabbalistic concepts for new perspectives on Golijov’s work. The first section introduces Kabbalah, ideas of balance, and musical gesture theory before presenting an overview of the Kabbalistic interpretation of creation and the klezmer oral tradition. The second section is an analysis of the work through form and harmony, musical gestures, and the narrative gestural connections to Kabbalah. The blending of these three analytical techniques provides an overview of the divine attributes present in Golijov’s work. The final section highlights the role of understanding versus interpretation, which plays a major role in both oral tradition and musical performance. Through this analysis, a deeper understanding of the work is created and implications for klezmer performance are introduced. A final discussion on the role of the ensemble within the narrative analysis, supported by the theological background of Kabbalah, concludes the section on understanding

231Pa and 230Th in the Arctic Ocean 1991-2015: Changes in the Eurasian and Makarov Basins

230Th and 231Pa are produced in sea water by radioactive decay of Uranium isotopes (234U, 235U). Both are particle reactive and are scavenged onto settling particles. As 230Th is more particle reactive than 231Pa, their distribution in the water column and activity ratio give information about particle fluxes and circulation patterns and –intensities. Both particle fluxes and deep water circulation may respond to climatic changes in the Arctic Ocean. This study discusses temporal changes in radionuclide concentration in the context of climate change. We compare results from 1991 [1] 2007 and 2015. We present results of dissolved 231Pa and 230Th activities of samples collected in the Nansen-, Amundsenand Makarov Basins during GEOTRACES sections GIPY11 (2007, 4 stations), GN04 (2015, 10 stations) aboard RV Polarstern. Our discussion of factors controlling the 230Th and 231Pa distribution is supported by, dissolved CFC, dissolved iron and particulate 230Th and 231Pa (3 stations) collected during GEOTRACES section GN04. We find that distributions and concentrations of dissolved 231Pa and 230Th in the central Arctic Ocean have changed significantly since 1991. Dissolved 231Pa concentrations in the Makarov basin decreased by half within less than 20 years. These changes are discussed in the context of environmental changes, such as declining sea ice cover and related increase of particle fluxes or changing deep water circulation. [1] Scholten, J. C., et al. (1995). Deep-Sea Research II 42: 1519- 153

Phenazine–naphthalene-1,5-diamine–water (1/1/2)

The asymmetric unit of the title compound, C12H8N2·C10H10N2·2H2O, contains one half-mol­ecule of phenazine, one half-mol­ecule of naphthalene-1,5-diamine and one water mol­ecule. The phenazine and naphthalene-1,5-diamine mol­ecules are located on inversion centers. The water mol­ecules serve as bridges between the naphthalene-1,5-diamine mol­ecules and also between the naphthalene-1,5-diamine and phenazine mol­ecules. The naphthalene-1,5-diamine and water mol­ecules are connected via N—H⋯O and O—H⋯N hydrogen bonds, forming a T4(2) motif. They are arranged into a two-dimensional polymeric structure parallel to (10) in which the water mol­ecule is a single donor and a double acceptor, whereas the amino group is a double donor and a single acceptor in the hydrogen bonding. These two-dimensional assemblies alternate with the layers of phenazine mol­ecules arranged into a herringbone motif. Each phenazine mol­ecule is hydrogen bonded to two water mol­ecules and thus a three-dimensional framework of hydrogen-bonded mol­ecules is generated

Quinoxaline–3-amino­phenol–water (2/1/2)

The asymmetric unit of the title compound, 2C8H6N2·C6H7NO·2H2O, contains two quinoxaline mol­ecules, one mol­ecule of 3-amino­phenol and two water mol­ecules which are hydrogen bonded to form a two-dimensional polymeric structure. Each of the symmetry-independent quinoxaline mol­ecules forms separate stacks of different symmetry. In one set of stacks, the mol­ecules are related by a screw axis and are slightly tilted [dihedral angle = 7.12 (1)°]. In the second set of stacks, adjacent mol­ecules are parallel and related by an inversion center [inter­planar distances = 3.376 (4) and 3.473 (4) Å]

The politics of in/visibility: carving out queer space in Ul'yanovsk

<p>In spite of a growing interest within sexualities studies in the concept of queer space (Oswin 2008), existing literature focuses almost exclusively on its most visible and territorialised forms, such as the gay scene, thus privileging Western metropolitan areas as hubs of queer consumer culture (Binnie 2004). While the literature has emphasised the political significance of queer space as a site of resistance to hegemonic gender and sexual norms, it has again predominantly focused on overt claims to public space embodied in Pride events, neglecting other less open forms of resistance.</p><p> This article contributes new insights to current debates about the construction and meaning of queer space by considering how city space is appropriated by an informal queer network in Ul’ianovsk. The group routinely occupied very public locations meeting and socialising on the street or in mainstream cafés in central Ul’ianovsk, although claims to these spaces as queer were mostly contingent, precarious or invisible to outsiders. The article considers how provincial location affects tactics used to carve out communal space, foregrounding the importance of local context and collective agency in shaping specific forms of resistance, and questioning ethnocentric assumptions about the empowering potential of visibility.</p&gt

5-Amino-1-naphthol

In the title compound, C10H9NO, the amino and the hydr­oxy groups act both as a single donor and a single acceptor in hydrogen bonding. In the crystal, mol­ecules are connected via chains of inter­molecular ⋯N—H⋯O—H⋯ inter­actions, forming a two-dimensional polymeric structure resembling the hydrogen-bonded mol­ecular assembly found in the crystal structure of naphthalene-1,5-diol. Within this layer, mol­ecules related by a translation along the a axis are arranged into slipped stacks via π–π stacking inter­actions [inter­planar distance = 3.450 (4) Å]. The amino N atom shows sp 3 hybridization and the two attached H atoms are located on the same side of the aromatic ring