Correlation functions and representation bases in free N=4 Super Yang-Mills

We study exact correlation functions of N=4 SYM at zero coupling. It has been known that it is convenient to label local gauge invariant operators by irreducible representations of symmetric groups/Brauer algebras. We first review the construction of representation bases from the viewpoint of the enhanced symmetry structure of the free theory. We present a basis of multi-matrix models using elements of Brauer algebras, generalising our previous construction for two matrices. We will compute multi-point functions of the basis with the exact N-dependence. In particular we study three-point functions of a class of BPS operators, and we find that they are given by a branching rule of the Brauer algebra. The three-point functions take a factorised form if representations on the operators satisfy a relation.Comment: 28 pages, typos correcte

One-electron bands, quantum Monte Carlo, and real superconductors

We use the doped Fullerenes as an example of how realistic systems can be described by simple models. Starting from the band structure we set up a tight-binding model that describes the t_{1u} conduction band. Adding correlation terms we arrive at a generalized Hubbard Hamiltonian that we treat using quantum Monte Carlo. To address the problem of superconductivity in the doped Fullerenes, we study the screening of a point charge. We find surprisingly efficient metallic screening even for strong correlations, almost up to the Mott transition, and discuss the implications on superconductivity, in particular the effect of the efficient screening on the Coulomb pseudopotential and the electron-phonon coupling.Comment: 9 pages LaTeX with 2 eps figures; Proceedings of the International Conference on Statistical Mechanics and Strongly Correlated Electrons in honor of Giovanni Paladin, Sept 27-29, 1999, Universita di Roma "La Sapienza"; additional material available at http://www.mpi-stuttgart.mpg.de/docs/ANDERSEN/fullerene

Introduction [for chapter on Consciousness]

No abstract

Stroop interference with Sesame Street Characters

The Stroop task is a robust task, making it a useful assessment of automatic processing, it is also associated with reading ability. This limits the utility of the Stroop task to children with a sufficient reading level. Non-word Stroop tasks may be alternatives for non-readers or beginning readers. For example, Prevor and Diamond (2005) showed that Stroop interference could be obtained using pictures (e.g., heart, frog). This study explored using Sesame Street characters to create Stroop interference. Elmo, Kermit, and Cookie Monster were shown in red, green, and blue to first through fourth grade students. RTs for color incongruent trials were close to 100 msec slower than color congruent trials indicating Stroop interference (d = .96). Therefore, this modified version of the Stroop appears to be an acceptable picture-based measure of automatic processing in elementary age students

Baryon number conservation and the cumulants of the net proton distribution

We discuss the modification of the cumulants of the net baryon and net proton distributions due to the global conservation of baryon number in heavy-ion collisions. Corresponding probability distributions and their cumulants are derived analytically. We show that the conservation of baryon number results in a substantial decrease of higher order cumulants. Based on our studies, we propose an observable that is insensitive to the modifications due to baryon number conservation.Comment: 6 pages, 4 figures, to be published in Phys. Rev.

Quantizing Geometry or Geometrizing the Quantum?

The unsatisfactory status of the search for a consistent and predictive quantization of gravity is taken as motivation to study the question whether geometrical laws could be more fundamental than quantization procedures. In such an approach the quantum mechanical laws should emerge from the geometrical theory. A toy model that incorporates the idea is presented and its necessary formulation in configuration space is emphasized.Comment: Talk given at QTRF 5 conference, 5 pages, typos corrected, reference adde