We review two important non-perturbative approaches for extracting the physics of low-
dimensional strongly correlated quantum systems. Firstly, we start by providing a …

The problem of two-dimensional localization in the presence of a magnetic field is
reconsidered. The existence of extended electronic states is demonstrated by use of the …

This is an attempt to describe the subject and the methodology of string theory as we
understand them today, ie, the entire set of problems which attract attention of theorists …

The localization transition observed in the quantum Hall effect may be explained by a critical
point in U (n)/U (m)× U (n− m) non-linear σ-models at topological angle θ= π in the replica …

The critical behaviour of SU (n) quantum “spin” chains, Wess-Zumino-Witten σ-models and
grassmanian σ-models at topological angle θ= π (of possible relevance to the quantum Hall …

Using a Kac-Moody current algebra with U (1/1)× U (1/1) graded symmetry, we describe a
class of (possibly disordered) critical points in two spatial dimensions. The critical points are …

The critical exponents of continuous phase transitions of a Hermitian system depend on and
only on its dimensionality and symmetries. This is the celebrated notion of the universality of …

An N-channel generalization of the network model of Chalker and Coddington is
considered. The model for N= 1 is known to describe the critical behavior at the plateau …

A solution to the long-standing problem of identifying the conformal field theory governing
the transition between quantized Hall plateaus of a disordered noninteracting 2d electron …

Logarithmic conformal field theories (LCFT) play a key role, for instance, in the description of
critical geometrical problems (percolation, self-avoiding walks, etc), or of critical points in …