Abelian gerbe and its application to field theory

Some errors are corrected.

Unified and condensed version (40 pages, PDF )

Separeted original version

Introduction (11 pages, PDF )

Sheaf (17 pages, PDF )

Circle bundles (19 pages, PDF )

Gerbes, I (5 pages, PDF )

Gerbes, II (30 pages, PDF )

Gerbes, III (19 pages, PDF )

Application, I (20 pages, PDF )

Application, II (12 pages, PDF )

Application, III (13 pages, PDF )

Reference (4 pages, DVI )