Yongbin Ruan
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Title: Mirror symmetry and modular forms
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Abstract: Traditionally, we use mirror symmetry to map a
difficult problem (A-model) to an easier problem
(B-model). Recently, there is a great deal of activities in
mathematics to understand the modularity properties of
Gromov-Witten
theory, a phenomenon suggested by BCOV almost twenty years ago.
Mirror symmetry is again used in  a crucial way.  However, the
new usage of mirror does not map a difficult problem to easy
problem. Instead, we make both side of mirror symmetry to work
together in a deep way. I will explain this interesting
phenomenon in the talk.