ABJ Quadrality

We study physical consequences of adding orientifolds to the ABJ triality,which is among 3d N=6 superconformal Chern-Simons theory known as ABJ theory,type IIA string in AdS_4 x CP^3 and N=6 supersymmetric (SUSY) Vasiliev higherspin theory in AdS_4. After adding the orientifolds, it is known that the gaugegroup of the ABJ theory becomes O(N_1)xUSp(2N_2) while the background of thestring theory is replaced by AdS_4 x CP^3/Z_2, and the supersymmetries in theboth theories reduce to N=5. We propose that adding the orientifolds to the N=6Vasiliev theory leads to N=5 SUSY Vasiliev theory. It turns out that the N=5case is more involved because there are two formulations of the N=5 Vasilievtheory with either O or USp internal symmetry. We show that the two N=5Vasiliev theories can be understood as certain projections of the N=6 Vasilievtheory, which we identify with the orientifold projections in the Vasilievtheory. We conjecture that the O(N_1)xUSp(2N_2) ABJ theory has the two vectormodel like limits: N_2 >> N_1 and N_1 >> N_2 which correspond to thesemi-classical N=5 Vasiliev theories with O(N_1) and USp(2N_2) internalsymmetries respectively. These correspondences together with the standardAdS/CFT correspondence comprise the ABJ quadrality among the N=5 ABJ theory,string/M-theory and two N=5 Vasliev theories. We provide a precise holographicdictionary for the correspondences by comparing correlation functions of stresstensor and flavor currents. Our conjecture is supported by various evidencesuch as agreements of the spectra, one-loop free energies and SUSY enhancementon the both sides. We also predict the leading free energy of the N=5 Vasilievtheory from the CFT side. As a byproduct, we give a derivation of the relationbetween the parity violating phase in the N=6 Vasiliev theory and theparameters in the N=6 ABJ theory, which was conjectured in arXiv:1207.4485.

Dynamic Polarization and Relaxation of 75As Nuclei in Silicon at High Magnetic Field and Low Temperature

We present the results of experiments on dynamic nuclear polarization and relaxation of 75As in silicon crystals. Experiments are performed in strong magnetic fields of 4.6 T and temperatures below 1 K. At these conditions donor electron spins are fully polarized, and the allowed and forbidden electron spin resonance transitions are well resolved. We demonstrate effective nuclear polarization of 75As nuclei via the Overhauser effect on the time scale of several hundred seconds. Excitation of the forbidden transitions leads to a polarization through the solid effect. The relaxation rate of donor nuclei has strong temperature dependence characteristic of Orbach process.

A simple method for the preparation of 3,5-dinitrimino-1,2,4-triazole and its salts

Текст статьи не публикуется в открытом доступе в соответствии с политикой журнала.The reaction of 2-methyl-1-nitrоisothiourea with hydrazine in the presence of alkali metal bicarbonates (carbonates) resulted in the formation of 3,5-dinitrimino-1,2,4-triazole salts. The same salts were also formed by a reaction of 2-methyl-1-nitrоisothiourea with alkali metal salts of 4-nitrоsemicarbazide. This represents the first synthesis and characterization of the high-energy 3,5-dinitrimino-1,2,4-triazole, which can be readily isolated by treatment of its disodium salt with HCl

The computational complexity of the initial value problem for the three body problem

The paper is concerned with the computational complexity of the initial valueproblem (IVP) for a system of ordinary dynamical equations. Formal problemstatement is given, containing a Turing machine with an oracle for getting theinitial values as real numbers. It is proven that the computational complexityof the IVP for the three body problem is not bounded by a polynomial. The proofis based on the analysis of oscillatory solutions of the Sitnikov problem thathave complex dynamical behavior. These solutions contradict the existence of analgorithm that solves the IVP in polynomial time.

SFCOMPO-2.0: An OECD NEA database of spent nuclear fuel isotopic assays, reactor design specifications, and operating data

sw ApoMb Amyloid Aggregation under Nondenaturing Conditions: The Role of Native Structure Stability

Investigation of the molecular mechanisms underlying amyloid-related human diseases attracts close attention. These diseases, the number of which currently is above 40, are characterized by formation of peptide or protein aggregates containing a cross-β structure. Most of the amyloidogenesis mechanisms described so far are based on experimental studies of aggregation of short peptides, intrinsically disordered proteins, or proteins under denaturing conditions, and studies of amyloid aggregate formations by structured globular proteins under conditions close to physiological ones are still in the initial stage. We investigated the effect of amino acid substitutions on propensity of the completely helical protein sperm whale apomyoglobin (sw ApoMb) for amyloid formation from its structured state in the absence of denaturing agents. Stability and aggregation of mutated sw ApoMb were studied using circular dichroism, Fourier transform infrared spectroscopy, x-ray diffraction, native electrophoresis, and electron microscopy techniques. Here, we demonstrate that stability of the protein native state determines both protein aggregation propensity and structural peculiarities of formed aggregates. Specifically, structurally stable mutants show low aggregation propensity and moderately destabilized sw ApoMb variants form amyloids, whereas their strongly destabilized mutants form both amyloids and nonamyloid aggregates.

Paratethys response to the Messinian salinity crisis

Approximating weighted neighborhood independent sets

A neighborhood independent set (NI-set) is a subset of edges in a graph such that the closed neighborhood of any vertex contains at most one edge of the subset. Finding a maximum cardinality NI-set is an NP-complete problem. We consider the weighted version of this problem. For general graphs we give an algorithm with approximation ratio Δ, and for diamond-free graphs we give a ratio Δ / 2 + 1 , where Δ is the maximum degree of the input graph. Furthermore, we show that the problem is polynomially solvable on cographs. Finally, we give a tight upper bound on the cardinality of a NI-set on regular graphs.

On recovering Sturm-Liouville operators with frozen argument from the spectrum

We consider second order linear differential operators possessing a termdepending on the unknown function with a fixed argument and study theuniqueness of recovering the operators from the spectrum. We also obtain aconstructive procedure for solving this inverse problem along with necessaryand sufficient conditions of its solvability.

Magnetic and magnetotransport properties of Bi$_2$Se$_3$ thin films doped by Eu

Structural, magnetic and magnetotransport properties of(Bi$_{1-x}$Eu$_x$)$_2$Se$_3$ thin films have been studied experimentally as afunction of Eu content. The films were synthesized by MBE. It is demonstratedthat Eu distribution is not uniform, it enter quint-layers forming inside themplain (pancake-like) areas containing Eu atoms, which sizes and concentrationincrease with the growth of Eu content. Positive magnetoresistance related tothe weak antilocalization was observed up to 15K. The antilocalization was notfollowed by weak localization as theory predicts for nontrivial topologicalstates. Surprisingly, the features of antilocalization were seen even at Eucontent $x$ $=$ 0.21. With the increase of Eu content the transition toferromagnetic state occurs at $x$ about 0.1 and with the Curie temperature$\approx$ 8K, that rises up to 64K for $x$ $=$ 0.21. At temperatures above 1-2K, the dephasing length is proportional to $T^{-1/2}$ indicating the dominantcontribution of inelastic $e-e$ scattering into electron phase breaking.However, at low temperatures the dephasing length saturates, that could be dueto the scattering on magnetic ions.