Yu, Kunrui  
   Hong Kong University of Science and Technology. Transcendental number theory, diophantine approximation.
   http://www.math.ust.hk/faculty/makryu/

Yang, Tonghai  
   SUNY at Stony Brook. Number theory, representation theory, and arithmetic geometry: especially L-functions, Eisenstein series, theta series, Shimura varieties, intersection theory, and elliptic curves.
   http://www.math.sunysb.edu/~thyang/

Ye, Yangbo  
   University of Iowa. Automorphic forms, Group representations, Automorphic L-functions, Relative trace formulae, Exponential sums, Distribution of primes.
   http://www.math.uiowa.edu/~yey/

Yukie, Akihiko  
   Tohoku University. Geometric invariant theory, Zeta functions for prehomogeneous vector spaces, Applications to the Oppenheim conjecture.
   http://www.math.tohoku.ac.jp/~yukie/

Yildirim, Yalcin  
   Bogaziçi University. Small gaps between consecutive primes.
   http://www.math.boun.edu.tr/instructors/yildirim/yildirim.htm

Young, Paul Thomas  
   College of Charleston. Sequences, L-functions.
   http://math.cofc.edu/faculty/paul/

Yamamoto, Yoshihiko  
   Osaka University. Class groups, Construction of class fields, Fundamental units, Elliptic curves, Abelian varieties, Jacobians, Automorphic forms, Zeta functions.
   http://www.math.sci.osaka-u.ac.jp/~yamamoto/

Yu, Chia-Fu  
   Columbia University. Shimura varieties; Dieudonne modules and p-divisible groups.
   http://www.math.columbia.edu/~chiafu/

Yu, Jing  
   Academia Sinica, Taiwan. Number theory, Arithmetical algebraic geometry. Arithmetic of function fields, transcendence theory. Symbolic computation.
   http://www.sinica.edu.tw/math/html/research/JY-e.html

Yang, Jae-Hyun  
   Inha University. Automorphic forms, representation theory of Lie groups, invariant theory, moduli of abelian varieties, vector bundles, mirror symmetry.
   http://www.math.inha.ac.kr/~jhyang/index_eng.html

Yui, Noriko  
   Queen's University at Kingston, Ontario, Canada. Arithmetic algebraic geometry.
   http://www.mast.queensu.ca/~yui/

Yoshitomi, Kentaro  
   Kyoto University. Computational number theory. Elliptic curve and Jacobian arithmetic classes for LiDIA.
   http://www.math.kyoto-u.ac.jp/~yositomi/index.en.html

Young, Matthew P.  
   American Institute of Mathematics. Arithmetic of elliptic curves. Publications.
   http://www.aimath.org/~myoung/