DUALITIES IN 5 DIMENSIONS AND CHARGED STRING SOLUTIONS

We consider an eleven dimensional supergravity compactified on K3 x T- 2 and show that the resulting five dimensional theory has identical ma ssless states as that of a heterotic string compactified on a specific five torus T-5. The strong-weak coupling duality of the five dimensio nal theory is argued to represent a ten dimensional Type IIA string co mpactified on K3 x S-1, supporting the conjecture of string-string dua lity in six dimensions, In this perspective, we present a magnetically charged solution of the low energy heterotic string effective action in five dimensions with a charge defined on a three sphere S-3 due to the two form potential. We use the Poincare duality to replace the ant isymmetric two form with a gauge field in the effective action and obt ain a string solution with charge on a two sphere S-2 instead of that on a three sphere S-3 in the five dimensional spacetime. We note that the string-particle duality is accompanied by a change of topology fro m S-3 to S-2 and vice versa.