1,903,026 research outputs found
Renormalization Group Therapy
We point out a general problem with the procedures commonly used to obtain
improved actions from MCRG decimated configurations. Straightforward
measurement of the couplings from the decimated configurations, by one of the
known methods, can result into actions that do not correctly reproduce the
physics on the undecimated lattice. This is because the decimated
configurations are generally not representative of the equilibrium
configurations of the assumed form of the effective action at the measured
couplings. Curing this involves fine-tuning of the chosen MCRG decimation
procedure, which is also dependent on the form assumed for the effective
action. We illustrate this in decimation studies of the SU(2) LGT using
Swendsen and Double Smeared Blocking decimation procedures. A single-plaquette
improved action involving five group representations and free of this pathology
is given.Comment: 18 pages, 9 figures, 9 table
Oligosaccharides in Milk: Their Benefits and Future Utilization
The percentage of carbohydrate in the milk/colostrum of the mammalian is range from trace to over 10%, of which disaccharide lactose (Gal(β1-4)Glc) is usually constitutes the major part. Apart from the lactose (Gal(β1-4)Glc; Gal, D-galactose; Glc, D-glucose), the rest of carbohydrate components is composed of variety of sugars, commonly named as milk oligosaccharides. Human mature milk and colostrum contain 12 ~ 13 g/l and 22 ~ 24 g/l of oligosaccharides, respectively. In contrast, bovine colostrum contains more than 1 g/l oligosaccharides and this concentration rapidly decreases after 48 hr post partum. Most of human milk oligosaccharides (HMO) are resistant to digestion and absorption within the small intestine. Therefore they can reach the infant colon, where they can act as prebiotics that stimulate the growth of beneficial microorganisms such as various species of Bifidobacterium. They can also act as receptor analogues that inhibit the attachment of pathogenic microorganisms to the infant's colonic mucosa. A small part of the milk oligosaccharides is absorbed intact into the circulation and it has been hypothesized that these may act as immunomodulators. Generally, the bovine milk oligosaccharides are believed not to be absorbed by human adults or infants, thus making them available to be utilized as prebiotics or anti-infection materials. The colostrum of cows and other domestic farm animals is a potential source of free oligosaccharides, and oligosaccharides isolated from these natural sources can be utilized as functional foods or animal feedstuffs on the industrial scale
The Real Meaning of Complex Minkowski-Space World-Lines
In connection with the study of shear-free null geodesics in Minkowski space,
we investigate the real geometric effects in real Minkowski space that are
induced by and associated with complex world-lines in complex Minkowski space.
It was already known, in a formal manner, that complex analytic curves in
complex Minkowski space induce shear-free null geodesic congruences. Here we
look at the direct geometric connections of the complex line and the real
structures. Among other items, we show, in particular, how a complex world-line
projects into the real Minkowski space in the form of a real shear-free null
geodesic congruence.Comment: 16 page
Improving the improved action
We investigate the construction of improved actions by the Monte Carlo
Renormalization Group method in the context of SU(2) gauge theory utilizing
different decimation procedures and effective actions. We demonstrate that the
basic self-consistency requirement for correct application of MCRG, i.e. that
the decimated configurations are equilibrium configurations of the adopted form
of the effective action, can only be achieved by careful fine-tuning of the
choice of decimation prescription and/or action.Comment: 8 pages, 5 figure
The Akulov-Volkov Lagrangian, Symmetry Currents and Spontaneously Broken Extended Supersymmetry
A generalization of the Akulov-Volkov effective Lagrangian governing the self
interactions of the Nambu-Goldstone fermions associated with spontaneously
broken extended supersymmetry as well as their coupling to matter is presented
and scrutinized. The resulting currents associated with R-symmetry,
supersymmetry and space-time translations are constructed and seen to form a
supermultiplet structure.Comment: 17 pages, LaTeX; Title, abstract and introduction changes, references
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Twisted Boundary Conditions and Matching to the Effective Four Dimensional Theory
Nontrivial twisted boundary conditions associated with extra compact
dimensions produce an ambiguity in the value of the four dimensional coupling
constants of the renormalizable interactions of the twisted fields' zero modes.
Resolving this indeterminancy would require a knowledge of the exact form of
the higher dimensional action including the coefficients of higher dimensional
operators. For the case of moderately sized extra dimensions, the uncertainty
in the coupling constants can be of order one and may lead to modifications in
the stability of the model.Comment: 8 pages, REVTe
Study to minimize hydrogen embrittlement of ultrahigh-strength steels
Hydrogen-stress cracking in high-strength steels is influenced by hydrogen content of the material and its hydrogen absorption tendency. Non-embrittling cleaning, pickling, and electroplating processes are being studied. Protection from this hydrogen embrittlement is important to the aerospace and aircraft industries
The Effective Potential And Additional Large Radius Compactified Space-Time Dimensions
The consequences of large radius extra space-time compactified dimensions on
the four dimensional one loop effective potential are investigated for a model
which includes scalar self interactions and Yukawa coupling to fermions. The
Kaluza-Klein tower of states associated with the extra compact dimensions
shifts the location of the effective potential minimum and modifies its
curvature. The dependence of these effects on the radius of the extra dimension
is illustrated for various choices of coupling constants and masses. For large
radii, the consequence of twisting the fermion boundary condition on the
compactified dimensions is numerically found to produce but a negligible effect
on the effective potential.Comment: 14 pages, LaTeX, 6 Postscript figure
On a Classical, Geometric Origin of Magnetic Moments, Spin-Angular Momentum and the Dirac Gyromagnetic Ratio
By treating the real Maxwell Field and real linearized Einstein equations as
being imbedded in complex Minkowski space, one can interpret magnetic moments
and spin-angular momentum as arising from a charge and mass monopole source
moving along a complex world line in the complex Minkowski space. In the
circumstances where the complex center of mass world-line coincides with the
complex center of charge world-line, the gyromagnetic ratio is that of the
Dirac electron.Comment: 17 page
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