Directory

Yingfei Yi, Ph.D

Professor, Faculty of Science - Mathematics & Statistical Sciences
Contact Overview Announcements Courses Activities Publications

Contact

Professor, Faculty of Science - Mathematics & Statistical Sciences
Email
yingfei@ualberta.ca
Phone
(780) 492-0215
Address
501 Central Academic Building
11324 - 89 Ave NW
Edmonton AB
T6G 2G1

Overview

Research

My research focuses on Dynamical Systems and Differential Equations, concerning both theoretical developments and applications. Areas I have been working on include Stochastic Differential Equations, Fokker-Planck Equations, Hamiltonian Systems, KAM Theory, Topological Dynamics, Ergodic Theory, Non-automatics Systems, Skew-Product Flows, Singular Perturbations, Mathematical Biology, Bifurcations, Invariant Manifolds Theory, Elliptic Equations, Parabolic Equations, Solitary Equations, and Variational Method. Publication


Announcements

    Annual IUSEP program 

    Courses

    MATH 315 - Calculus IV

    Vector calculus. Line and surface integrals. The divergence, Green's, and Stokes' theorems. Differential forms. Prerequisite: One of MATH 102, 125 or 127, and either MATH 214 or MATH 217. Notes: Credit can be obtained in at most one of MATH 215 and MATH 315. This course may not be taken for credit if credit has already been obtained in MATH 209 or 317.

    Fall Term 2025

    MATH 524 - Ordinary Differential Equations IIA

    Existence theorems, uniqueness theorems; linear systems (basic theory); stability (basic theory); nonlinear systems (local theory); nonlinear systems (global theory); bifurcations. Prerequisite: MATH 334 or 336, or equivalent.

    Fall Term 2025

    Browse more courses taught by Yingfei Yi

    Scholarly Activities

    Research - Co-Chair, Executive Committee

    Hale Conference Series in Dynamics of Differential Equations

    Research - Co-Editor-in-Chief

    Journal of Dynamics and Differential Equations

    Research - Editor

    Journal of Differential Equations and Dynamical Systems

    Research - Editor

    Differential and Integral Equations

    Research - Handling Editor

    Journal of Differential Equations

    Research - Member, Executive Committee

    Americas Conference Series in Differential Equations and Nonlinear Analysis

    Featured Publications

    Systematic measures of biological networks, Part II: Degeneracy, complexity and robustness

    Y. Li and Y. Yi

    Comm. Pure Appl. Math.. 2016 January; To appear

    Turing points and relaxation oscillation cycles in simple epidemic models

    M. Li, W. Liu, C. Shan, and Y. Yi

    SIAM J. Appl. Math.. 2016 January; 76 (2):663-687

    Interior regularity for regional fractional Laplacian

    C. Mou and Y. Yi

    Comm. Math. Phys.. 2015 January; 340

    Integral identity and measure estimates for stationary Fokker-Planck equations

    W. Huang, M. Ji, Z. Liu, and Y. Yi

    Ann. Probab.. 2015 January; 43 (4):1712-1730

    Viscous stability of quasi-periodic tori

    Z. Liang, J. Yan, and Y. Yi

    Ergod. Th. Dynam. Sys.. 2014 January; 34

    Invariant tori for Hamiltonian systems with high order proper degeneracy

    Y. Han, Y. Li, Y. Li

    Ann. Henri Poincare. 2010 January; 10 (8):1419-1436

    Almost periodically forced circle flow

    W. Huang and Y. Yi

    J. Funct. Anal.. 2009 January; 257 (3):832-902

    Quasi-periodic breathers in Hamiltonian networks of long-range coupling

    J. Geng, J. Viveros, and Y. Yi

    Physica D. 2008 January; 237

    A local variational principle of pressure and its applications to equilibrium states

    W. Huang and Y. Yi

    Israel J. Math.. 2007 January; 161

    Persistence of lower dimensional tori of general types in Hamiltonian systems

    Y. Li and Y. Li

    Trans. Amer. Math. Soc.. 2005 January; 357

    A quasi-periodic Poincare's theorem

    Y. Li and Y. Li

    Math. Annalen. 2003 January; 326

    The cyclicity of period annulus of degenerate quadratic Hamiltonian system with elliptic seg- ment

    S.-N. Chow, C. Li, and Y. Yi

    Ergod. Th. Dynam. Sys.. 2002 January; 22

    Center manifolds of invariant manifolds

    S.-N. Chow, W. Liu, and Y. Yi

    Trans. Amer. Math. Soc.. 2000 January; 352 (11):5179-5211

    Almost automorphic and almost periodic dynamics in skew-product semi-flows

    W. Shen and Y. Yi

    Memoirs Amer. Math. Soc.. 1998 January; 136 (647):1-93

    On minimal sets of scalar parabolic equations with skew-product structure

    W. Shen and Y. Yi

    Trans. Amer. Math. Soc.. 1995 January; 347 (11):4413-4431