Finite-Temperature and -Density QED: Schwinger-Dyson Equation in the Real-Time Formalism

Based on the real-time formalism, especially, on Thermo Field Dynamics, we derive the Schwinger-Dyson gap equation for the fermion propagator in QED and Four-Fermion model at finite-temperature and -density. We discuss some advantage of the real-time formalism in solving the self-consistent gap equation, in comparison with the ordinary imaginary-time formalism. Once we specify the vertex function, we can write down the SD equation with only continuous variables without performing the discrete sum over Matsubara frequencies which cannot be performed in advance without further approximation in the imaginary-time formalism. By solving the SD equation obtained in this way, we find the chiral-symmetry restoring transition at finite-temperature and present the associated phase diagram of strong coupling QED. In solving the SD equation, we consider two approximations: instantaneous-exchange and $p_0$-independent ones. The former has a direct correspondence in the imaginary time formalism, while the latter is a new approximation beyond the former, since the latter is able to incorporate new thermal effects which has been overlooked in the ordinary imaginary-time solution. However both approximations are shown to give qualitatively the same results on the finite-temperature phase transition.Comment: 28 pages+15 figures (figures: not included, available upon request

(D+1)-Dimensional Formulation for D-Dimensional Constrained Systems

D-dimensional constrained systems are studied with stochastic Lagrangian and\break Hamiltonian. It is shown that stochastic consistency conditions are second class constraints and Lagrange multiplier fields can be determined in (D+1)-dimensional canonical formulation. The Langevin equations for the constrained system are obtained as Hamilton's equations of motion where conjugate momenta play a part of noise fields.Comment: 10 pages (Plain TeX), CHIBA-EP-58-Re

Asymptotics for penalized additive B-spline regression

This paper is concerned with asymptotic theory for penalized spline estimator in bivariate additive model. The focus of this paper is put upon the penalized spline estimator obtained by the backfitting algorithm. The convergence of the algorithm as well as the uniqueness of its solution are shown. The asymptotic bias and variance of penalized spline estimator are derived by an efficient use of the asymptotic results for the penalized spline estimator in marginal univariate model. Asymptotic normality of estimator is also developed, by which an approximate confidence interval can be obtained. Some numerical experiments confirming theoretical results are provided.Comment: 24 pages, 6 figure

Dynamical Symmetry Breaking on Langevin Equation : Nambu ⋅\cdot Jona-Lasinio Model

In order to investigate dynamical symmetry breaking, we study Nambu$\cdot$Jona-Lasinio model in the large-N limit in the stochastic quantization method. Here in order to solve Langevin equation, we impose specified initial conditions and construct ``effective Langevin equation'' in the large-N limit and give the same non-perturbative results as path-integral approach gives. Moreover we discuss stability of vacuum by means of ``effective potential''.Comment: 12 pages (Plain TeX), 7 figures(not included, sorry!), CHIBA-EP-6

An education and negotiation of differences: the ‘schooling’ experiences of English-speaking Canadian children growing up with polio during the 1940s and 1950s

In this paper we present oral narratives focusing on schooling experiences of Canadians who lived with polio as children between 1940 and 1959. We argue that disabled students with polio received an education about the differences ascribed to them by individuals in authority (teachers, principals), by other young people, and through the dominant negative discourses of polio and normalizing, ableist practices of schooling. Using narrative accounts from participants’ interviews, we analyze their school experiences of difference: inaccessible physical and temporal spaces, bullying at school, exclusion from classes, and negotiating youth culture related to shoes, clothes and friendships. However, participants were not passive and they discussed how, along with families, they negotiated and occasionally defied normalizing processes. This research gives voice to a generation of disabled English-speaking Canadians, whose stories about school have not been heard before

Breaking the rules: Summer camping experiences and the lives of Ontario children growing up with polio in the 1940s and 1950s

This chapter presents an analysis from a critical disability studies history framework developed for a research project. It discusses how the research was conducted using an oral history method and how the analysis was produced. Oral history narratives of individuals living with polio are viewed as the most appropriate and important way to learn about and understand the meaning of polio for Canadians during the time period of 1927–1957. The chapter provides a historical backdrop to describe the development of some Ontario Society for Crippled Children (OSCC) camps, the philosophic basis for the camps, and the intended goals of the camping program. It deconstructs the philosophy of the OSCC, and presents some overarching themes. Each of the themes illustrates an aspect of the ableist dominant view of disability in relation to understandings of disabled children's lives at that time. The chapter introduces the counter narratives of the participants who attended these camps and their everyday lived experiences

Symplectic structure and monopole strength in 12C

The relation between the monopole transition strength and existence of cluster structure in the excited states is discussed based on an algebraic cluster model. The structure of $^{12}$C is studied with a 3$\alpha$ model, and the wave function for the relative motions between $\alpha$ clusters are described by the symplectic algebra $Sp(2,R)_z$, which corresponds to the linear combinations of $SU(3)$ states with different multiplicities. Introducing $Sp(2,R)_z$ algebra works well for reducing the number of the basis states, and it is also shown that states connected by the strong monopole transition are classified by a quantum number $\Lambda$ of the $Sp(2,R)_z$ algebra.Comment: Phys. Rev. C in pres