1,224 research outputs found
A Comparative Study of the Degree of Social Functioning of Children in the Church of God Home for Children, Sevierville, Tennessee
Purpose of the Study: It was this study\u27s purpose: (1) to compare the degree of social functioning of a sample of children who reside in an institutional environment with an equal sample of children who reside in individual family situations, (2) to suggest guide lines for the development of an instructional program to aid the children in the Church of God Home for Children with improving their individual social development if the suggestion for such a program is indicated by this study, and (3) to generate interest in additional research studies as a part of this institution\u27s program.
This study included children known to Child and Family Services in Knoxville, Tennessee, and children living in the Church of God Home for Children in Sevierville, Tennessee. The Church of God Home for Children was selected because the authors are personally involved with this institution\u27s program. The Child and Family Services was selected as a comparison group due to the willingness of its administration and its staff to cooperate in the study. Another reason for selecting this social agency was availability of children with social problems who come from similar socio-economic backgrounds as do children residing in the Church of God Home for Children
Canonical quantization of the WZW model with defects and Chern-Simons theory
We perform canonical quantization of the WZW model with defects and
permutation branes. We establish symplectomorphism between phase space of WZW
model with defects on cylinder and phase space of Chern-Simons theory on
annulus times with Wilson lines, and between phase space of WZW model
with defects on strip and Chern-Simons theory on disc times with
Wilson lines. We obtained also symplectomorphism between phase space of the
-fold product of the WZW model with boundary conditions specified by
permutation branes, and phase space of Chern-Simons theory on sphere with
holes and two Wilson lines.Comment: 26 pages, minor corrections don
Local Nature of Coset Models
The local algebras of the maximal Coset model C_max associated with a chiral
conformal subtheory A\subset B are shown to coincide with the local relative
commutants of A in B, provided A contains a stress energy tensor.
Making the same assumption, the adjoint action of the unique
inner-implementing representation U^A associated with A\subset B on the local
observables in B is found to define net-endomorphisms of B. This property is
exploited for constructing from B a conformally covariant holographic image in
1+1 dimensions which proves useful as a geometric picture for the joint
inclusion A\vee C_max \subset B.
Immediate applications to the analysis of current subalgebras are given and
the relation to normal canonical tensor product subfactors is clarified. A
natural converse of Borchers' theorem on half-sided translations is made
accessible.Comment: 33 pages, no figures; typos, minor improvement
String theories as the adiabatic limit of Yang-Mills theory
We consider Yang-Mills theory with a matrix gauge group on a direct
product manifold , where is a two-dimensional
Lorentzian manifold and is a two-dimensional open disc with the boundary
. The Euler-Lagrange equations for the metric on
yield constraint equations for the Yang-Mills energy-momentum tensor. We show
that in the adiabatic limit, when the metric on is scaled down, the
Yang-Mills equations plus constraints on the energy-momentum tensor become the
equations describing strings with a worldsheet moving in the based
loop group , where is the boundary of
. By choosing and putting to zero all parameters in besides , we get a string moving in . In
arXiv:1506.02175 it was described how one can obtain the Green-Schwarz
superstring action from Yang-Mills theory on while
shrinks to a point. Here we also consider Yang-Mills theory on a
three-dimensional manifold and show that in the limit when
the radius of tends to zero, the Yang-Mills action functional
supplemented by a Wess-Zumino-type term becomes the Green-Schwarz superstring
action.Comment: 11 pages, v3: clarifying remarks added, new section on embedding of
the Green-Schwarz superstring into d=3 Yang-Mills theory include
Cluster structures for 2-Calabi-Yau categories and unipotent groups
We investigate cluster tilting objects (and subcategories) in triangulated
2-Calabi-Yau categories and related categories. In particular we construct a
new class of such categories related to preprojective algebras of non Dynkin
quivers associated with elements in the Coxeter group. This class of
2-Calabi-Yau categories contains the cluster categories and the stable
categories of preprojective algebras of Dynkin graphs as special cases. For
these 2-Calabi-Yau categories we construct cluster tilting objects associated
with each reduced expression. The associated quiver is described in terms of
the reduced expression. Motivated by the theory of cluster algebras, we
formulate the notions of (weak) cluster structure and substructure, and give
several illustrations of these concepts. We give applications to cluster
algebras and subcluster algebras related to unipotent groups, both in the
Dynkin and non Dynkin case.Comment: 49 pages. For the third version the presentation is revised,
especially Chapter III replaces the old Chapter III and I
Birkhoff strata of the Grassmannian Gr: Algebraic curves
Algebraic varieties and curves arising in Birkhoff strata of the Sato
Grassmannian Gr are studied. It is shown that the big cell
contains the tower of families of the normal rational curves of all odd orders.
Strata , contain hyperelliptic curves of genus
and their coordinate rings. Strata , contain
plane curves for and and
curves in , respectively. Curves in the strata
have zero genus.Comment: 14 pages, no figures, improved some definitions, typos correcte
Persistence and Fadeout of Preschool Participation Effects on Early Reading Skills in Low- and Middle-Income Countries
The adoption of the Sustainable Development Goals (SDGs) in September 2015 marked a new milestone for early childhood education, care, and development. For the first time in the framework of global goals, preschool education was described as integral to children’s school readiness. Yet with few exceptions, much of the research on the impact of preschool has stemmed from high-income countries. Even fewer studies have examined preschool participation and later learning across multiple countries. This article helps fill this gap by connecting preschool participation to early primary reading outcomes, as measured by the Early Grade Reading Assessment. Drawing on a unique data set using student-level learning assessments from 16 countries, we use preprimary participation to explain primary school reading skills, including letter knowledge and oral reading fluency. We also model the influence of key demographic variables on these outcomes, including home language and classroom language of instruction (LOI). For a subset of six countries with exceptionally rich data, we examine national-level policy and practice to better understand what might explain the persistence or fadeout of the effect of preschool. Policy makers and practitioners alike will find these results useful in making cases for improving preschool experiences for children in low- and middle-income countries in the next decade of SDG-related efforts
News from the Virasoro algebra
It is shown that the local quantum field theory of the chiral energy-
momentum tensor with central charge coincides with the gauge invariant
subtheory of the chiral current algebra at level 1, where the gauge
group is the global symmetry. At higher level, the same scheme gives
rise to -algebra extensions of the Virasoro algebra.Comment: 4 pages, Latex, DESY 93-11
Fractional Loop Group and Twisted K-Theory
We study the structure of abelian extensions of the group of
-differentiable loops (in the Sobolev sense), generalizing from the case of
central extension of the smooth loop group. This is motivated by the aim of
understanding the problems with current algebras in higher dimensions. Highest
weight modules are constructed for the Lie algebra. The construction is
extended to the current algebra of supersymmetric Wess-Zumino-Witten model. An
application to the twisted K-theory on is discussed.Comment: Final version in Commun. Math. Phy
On Z-gradations of twisted loop Lie algebras of complex simple Lie algebras
We define the twisted loop Lie algebra of a finite dimensional Lie algebra
as the Fr\'echet space of all twisted periodic smooth mappings
from to . Here the Lie algebra operation is
continuous. We call such Lie algebras Fr\'echet Lie algebras. We introduce the
notion of an integrable -gradation of a Fr\'echet Lie algebra, and
find all inequivalent integrable -gradations with finite dimensional
grading subspaces of twisted loop Lie algebras of complex simple Lie algebras.Comment: 26 page
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