Abstract

The string theory is a fast moving subject, both physics wise and in the
respect of mathematics. In order to keep up with the discipline it is important
to move with new ideas which are being stressed. Here I wish to give
extracts from new papers of ideas which I have recently found interesting.
There are six papers which are involved:
I ."Strings formulated directly in 4 dimensions " A. N. Schellekens
II. "Remarks on 40 strings" C.Bachas
III. "Informal introduction to extended algebras and conformal field
theories with c 1 " F.Ravanini
IV. "Skein relations and braiding in topological gauge theory" and
"Modular geometry and the classification of rational conformal field
theories " S. Mukhi
V. "Chern-Simons theories" E. Witten
VI. "Duality and the rdl of nonperturbative effects on the world-sheet"
J.Lauer, J.Mas and H.P. Nilles