933 research outputs found
The conceptus induces a switch in protein expression and activities of superoxide dismutase 1 and 2 in the sheep endometrium during early pregnancy
Acknowledgements We thank Philippe Bolifraud (INRA, France), Krawiec Angele, Sandra Grange, Laurence Puillet-Anselme (CHU Grenoble, France) and Margaret Fraser (Aberdeen, UK) for their expert technical assistance. The authors also thank the staff of the sheep sheds of Jouy-en-Josas (INRA, France). The authors would also like to thank the anonymous reviewers for their close examination of this article and their useful comments. Funding This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.Peer reviewedPostprin
Compact Gauge Fields for Supersymmetric Lattices
We show that a large class of Euclidean extended supersymmetric lattice gauge
theories constructed in [hep-lat/0302017 - hep-lat/0503039] can be regarded as
compact formulations by using the polar decomposition of the complex link
fields. In particular, the gauge part of the supersymmetric lattice action is
the standard Wilson action. This formulation facilitates the construction of
gauge invariant operators.Comment: 15 pages, 2 figures. Minor change
Crossover of the weighted mean fragment mass scaling in 2D brittle fragmentation
We performed vertical and horizontal sandwich 2D brittle fragmentation
experiments. The weighted mean fragment mass was scaled using the multiplicity
. The scaling exponent crossed over at . In the
small regime, the binomial multiplicative (BM) model was
suitable and the fragment mass distribution obeyed log-normal form. However, in
the large regime, in which a clear power-law cumulative
fragment mass distribution was observed, it was impossible to describe the
scaling exponent using the BM model. We also found that the scaling exponent of
the cumulative fragment mass distribution depended on the manner of impact
(loading conditions): it was 0.5 in the vertical sandwich experiment, and
approximately 1.0 in the horizontal sandwich experiment.Comment: 5 pages, 3 figure
Twisted Supersymmetric Gauge Theories and Orbifold Lattices
We examine the relation between twisted versions of the extended
supersymmetric gauge theories and supersymmetric orbifold lattices. In
particular, for the SYM in , we show that the continuum
limit of orbifold lattice reproduces the twist introduced by Marcus, and the
examples at lower dimensions are usually Blau-Thompson type. The orbifold
lattice point group symmetry is a subgroup of the twisted Lorentz group, and
the exact supersymmetry of the lattice is indeed the nilpotent scalar
supersymmetry of the twisted versions. We also introduce twisting in terms of
spin groups of finite point subgroups of -symmetry and spacetime symmetry.Comment: 32 page
Magnetic phases of electron-doped, infinite-layer SrLaCuO from first-principles density functional calculations
The magnetic phases of electron-doped, infinite-layer
are elucidated by
first-principles density functional calculations. We describe the
antiferromagnetic parent state, metallic phase transition, lattice structure
and magnetic anisotropy evolution upon doping, as well as pressure-induced
changes to the density of states at Fermi level that are consistent with
experiments where comparison is possible. We investigate low-energy states with
multiple magnetic configurations and study their specific heat coefficients and
magnetic exchange coupling, as well as the density of states at Fermi level.
The latter quantity is used to study the effects of spin fluctuations on the
electronic structure of this strongly correlated material.Comment: 15 pages, 9 figure
Efficient method for simulating quantum electron dynamics under the time dependent Kohn-Sham equation
A numerical scheme for solving the time-evolution of wave functions under the
time dependent Kohn-Sham equation has been developed. Since the effective
Hamiltonian depends on the wave functions, the wave functions and the effective
Hamiltonian should evolve consistently with each other. For this purpose, a
self-consistent loop is required at every time-step for solving the
time-evolution numerically, which is computationally expensive. However, in
this paper, we develop a different approach expressing a formal solution of the
TD-KS equation, and prove that it is possible to solve the TD-KS equation
efficiently and accurately by means of a simple numerical scheme without the
use of any self-consistent loops.Comment: 5 pages, 3 figures. Physical Review E, 2002, in pres
T-Duality Transformation and Universal Structure of Non-Critical String Field Theory
We discuss a T-duality transformation for the c=1/2 matrix model for the
purpose of studying duality transformations in a possible toy example of
nonperturbative frameworks of string theory. Our approach is to first
investigate the scaling limit of the Schwinger-Dyson equations and the
stochastic Hamiltonian in terms of the dual variables and then compare the
results with those using the original spin variables. It is shown that the
c=1/2 model in the scaling limit is T-duality symmetric in the sphere
approximation. The duality symmetry is however violated when the higher-genus
effects are taken into account, owing to the existence of global Z_2 vector
fields corresponding to nontrivial homology cycles. Some universal properties
of the stochastic Hamiltonians which play an important role in discussing the
scaling limit and have been discussed in a previous work by the last two
authors are refined in both the original and dual formulations. We also report
a number of new explicit results for various amplitudes containing macroscopic
loop operators.Comment: RevTex, 46 pages, 5 eps figure
Lattice formulation of two-dimensional N=(2,2) super Yang-Mills with SU(N) gauge group
We propose a lattice model for two-dimensional SU(N) N=(2,2) super Yang-Mills
model. We start from the CKKU model for this system, which is valid only for
U(N) gauge group. We give a reduction of U(1) part keeping a part of
supersymmetry. In order to suppress artifact vacua, we use an admissibility
condition.Comment: 16 pages, 3 figures; v2: typo crrected; v3: 18 pages, a version to
appear in JHE
Deformed matrix models, supersymmetric lattice twists and N=1/4 supersymmetry
A manifestly supersymmetric nonperturbative matrix regularization for a
twisted version of N=(8,8) theory on a curved background (a two-sphere) is
constructed. Both continuum and the matrix regularization respect four exact
scalar supersymmetries under a twisted version of the supersymmetry algebra. We
then discuss a succinct Q=1 deformed matrix model regularization of N=4 SYM in
d=4, which is equivalent to a non-commutative orbifold lattice
formulation. Motivated by recent progress in supersymmetric lattices, we also
propose a N=1/4 supersymmetry preserving deformation of N=4 SYM theory on
. In this class of N=1/4 theories, both the regularized and continuum
theory respect the same set of (scalar) supersymmetry. By using the equivalence
of the deformed matrix models with the lattice formulations, we give a very
simple physical argument on why the exact lattice supersymmetry must be a
subset of scalar subalgebra. This argument disagrees with the recent claims of
the link approach, for which we give a new interpretation.Comment: 47 pages, 3 figure
Supersymmetric Deformations of Type IIB Matrix Model as Matrix Regularization of N=4 SYM
We construct a supersymmetry and global symmetry
preserving deformation of the type IIB matrix model. This model, without
orbifold projection, serves as a nonperturbative regularization for
supersymmetric Yang-Mills theory in four Euclidean dimensions.
Upon deformation, the eigenvalues of the bosonic matrices are forced to reside
on the surface of a hypertorus. We explicitly show the relation between the
noncommutative moduli space of the deformed matrix theory and the Brillouin
zone of the emergent lattice theory. This observation makes the transmutation
of the moduli space into the base space of target field theory clearer. The
lattice theory is slightly nonlocal, however the nonlocality is suppressed by
the lattice spacing. In the classical continuum limit, we recover the
SYM theory. We also discuss the result in terms of D-branes and
interpret it as collective excitations of D(-1) branes forming D3 branes.Comment: Version 2: Extended discussion of moduli space, added a referenc
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