821 research outputs found
Super-Virasoro Anomaly, Super-Weyl Anomaly and the Super-Liouville Action for 2D Supergravity
The relation between super-Virasoro anomaly and super-Weyl anomaly in
NSR superstring coupled with 2D supergravity is investigated from canonical
theoretical view point. The WZW action canceling the super-Virasoro anomaly is
explicitly constructed. It is super-Weyl invariant but nonlocal functional of
2D supergravity. The nonlocality can be remedied by the super-Liouvlle action,
which in turn recovers the super-Weyl anomaly. The final gravitational
effective action turns out to be local but noncovariant super-Liouville action,
describing the dynamical behavior of the super-Liouville fields. The BRST
invariance of this approach is examined in the superconformal gauge and in the
light-cone gauge.Comment: 45 page
Chiral anomalies in the reduced model
On the basis of an observation due to Kiskis, Narayanan and Neuberger, we
show that there is a remnant of chiral anomalies in the reduced model when a
Dirac operator which obeys the Ginsparg-Wilson relation is employed for the
fermion sector. We consider fermions belonging to the fundamental
representation of the gauge group U(N) or SU(N). For vector-like theories, we
determine a general form of the axial anomaly or the topological charge within
a framework of a U(1) embedding. For chiral gauge theories with the gauge group
U(N), a remnant of gauge anomaly emerges as an obstruction to a smooth fermion
integration measure. The pure gauge action of gauge-field configurations which
cause these non-trivial phenomena always diverges in the 't Hooft
limit when d>2.Comment: 20 pages, uses JHEP.cls and amsfonts.sty, the final version to appear
in JHE
Structure and morphology of diamond-like carbon coated on nylon 66/poly(phenylene ether) alloy
In order to investigate the structure and morphology of diamond-like carbon (DLC) film coated on a polymer alloy prepared by a particular four-steps method in the plasma-based ion implantation and deposition (PBIID) process, studies were made on the structure and properties of the DLC film with special reference to its surface morphology by scanning (SEM) and transmission (TEM) electron microscopies. It is revealed from TEM microscopy that the amorphous structure of the DLC film consists of a silicon-implanted layer on the polymer substrate, a hard acetylene-implanted layer and a flexible acetylene/toluene-deposited layer. Some properties of the DLC film can be accounted for by the morphology examined in this study
Synthesis and electrochemistry of dimanganese(II) complexes of phenol-based dinucleating ligands with four methoxyethyl chelating arms
Dimanganese(II) complexes [Mn2(bonp)(PhCO2)2]PF6 (1) and [Mn2(bocp)(PhCO2)2]PF6 (2) were synthesized with p-nitro- and p-chloro-substituted phenol-based dinucleating ligands bonp- [2,6-bis[bis(2-methoxyethyl)aminomethyl]-4-nitrophenolate anion] and bocp- [4-chloro-2,6-bis[bis(2-methoxyethyl)aminomethyl]phenolate anion], respectively, with the aim of controlling the redox potentials of the dimanganese center by changing the p-substituents in the dinucleating ligands. Cyclic voltammograms of 1 and 2 showed quasi-reversible oxidation processes, assigned to MnIIMnII/MnIIMnIII, at 1.17 and 1.00 V vs. Ag/AgCl, respectively. Compared to the previous p-methyl complex [Mn2(bomp)(PhCO2)2]PF6 (3) [bomp–: 2,6-bis[bis(2-methoxyethyl)aminomethyl]-4-methylphenolate anion] (0.96 V vs. Ag/AgCl), the order of the potentials was 1(-NO2) > 2(-Cl) > 3(-CH3). Thus, the redox potentials of the dimanganese centers were controlled by the p-substituents in the dinucleating ligands
More about the axial anomaly on the lattice
We study the axial anomaly defined on a finite-size lattice by using a Dirac
operator which obeys the Ginsparg-Wilson relation. When the gauge group is
U(1), we show that the basic structure of axial anomaly on the infinite
lattice, which can be deduced by a cohomological analysis, persists even on
(sufficiently large) finite-size lattices. For non-abelian gauge groups, we
propose a conjecture on a possible form of axial anomaly on the infinite
lattice, which holds to all orders in perturbation theory. With this
conjecture, we show that a structure of the axial anomaly on finite-size
lattices is again basically identical to that on the infinite lattice. Our
analysis with the Ginsparg-Wilson Dirac operator indicates that, in appropriate
frameworks, the basic structure of axial anomaly is quite robust and it
persists even in a system with finite ultraviolet and infrared cutoffs.Comment: 12 pages, uses JHEP.cls and amsfonts.sty, the final version to appear
in Nucl. Phys.
Axial anomaly with the overlap-Dirac operator in arbitrary dimensions
We evaluate for arbitrary even dimensions the classical continuum limit of
the lattice axial anomaly defined by the overlap-Dirac operator. Our
calculational scheme is simple and systematic. In particular, a powerful
topological argument is utilized to determine the value of a lattice integral
involved in the calculation. When the Dirac operator is free of species
doubling, the classical continuum limit of the axial anomaly in various
dimensions is combined into a form of the Chern character, as expected.Comment: 9 pages, uses JHEP.cls and amsfonts.sty, the final version to appear
in JHE
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