747 research outputs found
Loop Equations for + and - Loops in c = 1/2 Non-Critical String Theory
New loop equations for all genera in non-critical string
theory are constructed. Our loop equations include two types of loops, loops
with all Ising spins up (+ loops) and those with all spins down ( loops).
The loop equations generate an algebra which is a certain extension of
algebra and are equivalent to the constraints derived before in the
matrix-model formulation of 2d gravity. Application of these loop equations to
construction of Hamiltonian for string field theory is
considered.Comment: 21 pages, LaTex file, no figure
Editorial: hypotheses about protein folding - the proteomic code and wonderfolds
Theoretical biology journals can contribute in many ways to the progress of knowledge. They are particularly well-placed to encourage dialogue and debate about hypotheses addressing problematical areas of research. An online journal provides an especially useful forum for such debate because of the option of posting comments within days of the publication of a contentious article
Stochastic Hamiltonian for Non-Critical String Field Theories from Double-Scaled Matrix Models
We present detailed discussions on the stochastic Hamiltonians for
non-critical string field theories on the basis of matrix models. Beginning
from the simplest case, we derive the explicit forms of the Hamiltonians
for the higher critical case (which corresponds to ) and for the
case , directly from the double-scaled matrix models. In particular, for
the two-matrix case, we do not put any restrictions on the spin configurations
of the string fields. The properties of the resulting infinite algebras of
Schwinger-Dyson operators associated with the Hamiltonians and the derivation
of the Virasoro and algebras therefrom are also investigated. Our results
suggest certain universal structure of the stochastic Hamiltonians, which might
be useful for an attempt towards a background independent string field theory.Comment: 70 pages, LaTeX, typographical errors are corrected, to be published
in Phys. Rev.
Age trajectories of glycaemic traits in non-diabetic South Asian and white individuals: the Whitehall II cohort study.
South Asian individuals have an increased prevalence of type 2 diabetes, but little is known about the development of glycaemic traits in this ethnic group. We compared age-related changes in glycaemic traits between non-diabetic South Asian and white participants
Exact Renormalization Group and Loop Equation
We propose a gauge invariant formulation of the exact renormalization group
equation for nonsupersymmetric pure U(N) Yang-Mills theory, based on the
construction by Tim Morris. In fact we show that our renormalization group
equation amounts to a regularized version of the loop equation, thereby
providing a direct relation between the exact renormalization group and the
Schwinger-Dyson equations. We also discuss a possible implication of our
formulation to the holographic correspondence of the bulk gravity and the
boundary gauge theory.Comment: 13 pages, Latex, References added. An error in eq. (6) fixed and a
few corrrections accordingly. Results unchange
Appearance of Human Plasma Cells Following Differentiation of Human B Cells in NOD/SCID Mouse Spleen
Relatively little is known for the differentiation and maturation process of human B cells to plasma cells. This is particularly important in reconstitution work involving transfer of autoantibodies. To address this issue, we transplanted human peripheral blood mononuclear cells (PBMC) directly into the spleen of irradiated NOD/SCID mice depleted of natural killer cell activity. Within 6 weeks, naïve B cells differentiated into memory B cells and, importantly, the numbers of human CD138+ plasma cells in spleen increased by 100 fold after transplantation. Plasma cell numbers correlated with the detection of human IgM and IgG in serum, indicating that human B cells had differentiated into mature plasma cells in the murine spleen. In addition to CD19+ plasma cells, a distinct CD19- plasma cell population was detected, suggesting that downregulation of CD19 associated with maturation of plasma cells occurred. When purified human B cells were transplanted, those findings were not observed. Our results indicate that differentiation and maturation of human B cells and plasma cells can be investigated by transplantation of human PBMC into the spleen of NOD/SCID mice. The model will be useful for studying the differentiation of human B cells and generation of plasma cells
On the Quantum Geometry of Multi-critical CDT
We discuss extensions of a recently introduced model of multi-critical CDT to
higher multi-critical points. As in the case of pure CDT the continuum limit
can be taken on the level of the action and the resulting continuum surface
model is again described by a matrix model. The resolvent, a simple observable
of the quantum geometry which is accessible from the matrix model is calculated
for arbitrary multi-critical points. We go beyond the matrix model by
determining the propagator using the peeling procedure which is used to extract
the effective quantum Hamiltonian and the fractal dimension in agreement with
earlier results by Ambjorn et al. With this at hand a string field theory
formalism for multi-critical CDT is introduced and it is shown that the
Dyson-Schwinger equations match the loop equations of the matrix model. We
conclude by commenting on how to formally obtain the sum over topologies and a
relation to stochastic quantisation.Comment: 15 pages, 2 figures, improved discussion, some new results regarding
Hausdorff dimension, as publishe
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