484 research outputs found
Five-Dimensional Supersymmetric Yang-Mills Theories and Random Plane Partitions
Five-dimensional supersymmetric Yang-Mills theories are
investigated from the viewpoint of random plane partitions. It is shown that
random plane partitions are factorizable as q-deformed random partitions so
that they admit the interpretations as five-dimensional Yang-Mills and as
topological string amplitudes. In particular, they lead to the exact partition
functions of five-dimensional supersymmetric Yang-Mills with
the Chern-Simons terms. We further show that some specific partitions, which we
call the ground partitions, describe the perturbative regime of the gauge
theories. We also argue their role in string theory. The gauge instantons give
the deformation of the ground partition.Comment: 33 pages, 9 figures, typos correcte
Spin Wave Resonance and Exchange Parameters in fcc Fe-Ni Alloys
Spin wave resonance for a series of fcc Fe-Ni alloys has been measured in order to study the exchange stiffness constant D. In general the resonance field vs the square of the spin wave mode number (n) curve is linear for high values of n, whereas some amount of deviation from linearity occurs for low values of n. This is considered to be due to the inhomogeneous demagnetizing field of the sample. We can determine the value of D from the linear part of the curve, provided we have a sufficient number of observed modes. As a supplementary means, we have also made low temperature magnetization measurements from which the value of D was derived. Consistency between these two kinds of measurements is ascertained. The composition dependence of D is not quite coincident with that derived from the neutron small angle scattering experiments by Hatherly et al. The data are discussed both from the standpoint of localized electron model and collective electron model
Production of Multiply Ionized Atoms by Ion-Atom Collisions (Commemoration Issue Dedicated to Professor Sakae Shimizu on the Occasion of his Retirement)
Melting Crystal, Quantum Torus and Toda Hierarchy
Searching for the integrable structures of supersymmetric gauge theories and
topological strings, we study melting crystal, which is known as random plane
partition, from the viewpoint of integrable systems. We show that a series of
partition functions of melting crystals gives rise to a tau function of the
one-dimensional Toda hierarchy, where the models are defined by adding suitable
potentials, endowed with a series of coupling constants, to the standard
statistical weight. These potentials can be converted to a commutative
sub-algebra of quantum torus Lie algebra. This perspective reveals a remarkable
connection between random plane partition and quantum torus Lie algebra, and
substantially enables to prove the statement. Based on the result, we briefly
argue the integrable structures of five-dimensional
supersymmetric gauge theories and -model topological strings. The
aforementioned potentials correspond to gauge theory observables analogous to
the Wilson loops, and thereby the partition functions are translated in the
gauge theory to generating functions of their correlators. In topological
strings, we particularly comment on a possibility of topology change caused by
condensation of these observables, giving a simple example.Comment: Final version to be published in Commun. Math. Phys. . A new section
is added and devoted to Conclusion and discussion, where, in particular, a
possible relation with the generating function of the absolute Gromov-Witten
invariants on CP^1 is commented. Two references are added. Typos are
corrected. 32 pages. 4 figure
Integrable Structure of Supersymmetric Yang-Mills and Melting Crystal
We study loop operators of SYM in background.
For the case of U(1) theory, the generating function of correlation functions
of the loop operators reproduces the partition function of melting crystal
model with external potential. We argue the common integrable structure of
SYM and melting crystal model.Comment: 12 pages, 1 figure, based on an invited talk presented at the
international workshop "Progress of String Theory and Quantum Field Theory"
(Osaka City University, December 7-10, 2007), to be published in the
proceeding
Free Fermion and Seiberg-Witten Differential in Random Plane Partitions
A model of random plane partitions which describes five-dimensional
supersymmetric SU(N) Yang-Mills is studied. We compute the wave
functions of fermions in this statistical model and investigate their
thermodynamic limits or the semi-classical behaviors. These become of the WKB
type at the thermodynamic limit. When the fermions are located at the main
diagonal of the plane partition, their semi-classical wave functions are
obtained in a universal form. We further show that by taking the
four-dimensional limit the semi-classical wave functions turn to live on the
Seiberg-Witten curve and that the classical action becomes precisely the
integral of the Seiberg-Witten differential. When the fermions are located away
from the main diagonal, the semi-classical wave functions depend on another
continuous parameter. It is argued that they are related with the wave
functions at the main diagonal by the renormalization group flow of the
underlying gauge theory.Comment: 32 pages, 3 figures, typos correcte
Occurrence of thiamin pyrophosphate-dependent 2-oxoglutarate decarboxylase in mitochondria of Euglena gracilis
Abstract2-Oxoglutarate decarboxylase which catalyzes the conversion of 2-oxoglutarate into succinate semialdehyde occurs in mitochondria of Euglena gracilis which lacks a 2-oxoglutarate dehydrogenase complex. The enzyme reaction required thiamin pyrophosphate, MgCl2, 2-mercaptoethanol and NADP+ for the maximum activity, and was not affected by pyruvate and oxalacetate. In the reaction, the enzyme consumed 2-oxoglutarate, evolved CO2 and formed succinate semialdehyde in stoichiometric relationship. The maximum enzyme activity was found at pH 7.0 and 40° C, and Km values for 2-oxoglutarate and thiamin pyrophosphate were 0.33 and 0.056 mM, respectively. These results indicate that the thiamin pyrophosphate-dependent Euglena decarboxylase belongs to a new type of decarboxylase to be designated as 2-oxoglutarate decarboxylase. The probable role of the new decarboxylase in Euglena mitochondria is discussed with regard to the tricarboxylic acid cycle
Gravitational Quantum Foam and Supersymmetric Gauge Theories
We study K\"{a}hler gravity on local SU(N) geometry and describe precise
correspondence with certain supersymmetric gauge theories and random plane
partitions. The local geometry is discretized, via the geometric quantization,
to a foam of an infinite number of gravitational quanta. We count these quanta
in a relative manner by measuring a deviation of the local geometry from a
singular Calabi-Yau threefold, that is a A_{N-1} singularity fibred over
\mathbb{P}^1. With such a regularization prescription, the number of the
gravitational quanta becomes finite and turns to be the perturbative
prepotential for five-dimensional \mathcal{N}=1 supersymmetric SU(N)
Yang-Mills. These quanta are labelled by lattice points in a certain convex
polyhedron on \mathbb{R}^3. The polyhedron becomes obtainable from a plane
partition which is the ground state of a statistical model of random plane
partition that describes the exact partition function for the gauge theory.
Each gravitational quantum of the local geometry is shown to consist of N unit
cubes of plane partitions.Comment: 43 pages, 12 figures: V2 typos correcte
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