Periods of algebraic cycles

The origin of Hodge theory goes back to many works on elliptic, abelian and multiple
integrals (periods). The talk will start with  some remarks on the books written  by E. Picard
and G. Simart in 1897 and 1906, where the origin of  Hodge conjecture lies.  Then I will discuss
periods of algebraic cycles and will give some applications in identifying some components
of the Noether-Lefschetz and Hodge locus.  The talk is based on my book under preparation
available in my web page (A course in Hodge Theory: With Emphasis on Multiple Integrals).