Professor, Associate Department Head Research Research Areas: Analysis Applied Mathematics Research Interests: Links of Interest The Fields Institute for Research in the Mathematical Sciences (located at the University of Toronto) Centre de Recherches Mathematiques (located at the University of Montreal) The Pacific Institute for the Mathematical Sciences (located at the University of British Columbia) The Courant Institute of Mathematical Sciences (located at New York University, New York) The Institute for Advanced Studies, Princeton, NJ Mathematical Sciences Research Institute in Berkeley, California The Isaac Newton Institute for Mathematical Sciences, Cambridge, England AMS: American Math Society AMS: Mathematical Reviews Information Canadian Math Society Other Mathematics Service Providers Cornell Theory Math and Science Gateway TMR - Harmonic Analysis AMS list of mathematics journals AMS bookstore - analysis Financial Mathematics Mathematics Genealogy Project Mathematical quotations Biographies of famous mathematicians College and University home pages Mathematics Web Sites xxx.lanl.gov preprints in Classical Analysis, Complex Variables , Functional Analysis, Differential Geometry, Spectral Theory and Analysis of PDE Zentralblatt Math database Mathematical Association of America SIAM: Society for Industrial and Applied Mathematics The World-Wide Web Virtual Library: Mathematics Unsolved Mathematics Problems Mathscinet Search. Harmonic Analysis Google Jstor Mathematics ArXiv mapquest mathematical journals TeX Support Getting started with LaTeX TeX Frequently asked Questions Comprehensive TeX Archive Network TeX Users Group LaTeX help 1.1 LaTeX symbol tables; more symbols All about LaTeX2HTML Latex Emacs etc. for PC Selected Publications Selected Publications: 1. The Inverse of Some Differential Operators on the Heisenberg Group,Comm. in PDEs. Vol.20 (7&8)(1995), 1275-1302. Abstract: By using the pseudo-differential operator methods introduced by Beals and Greiner in studying the fundamental solution for the Heisenberg Laplacian, we find the symbol of the inverse of a very interesting PDO and the corresponding kernel. It is interesting to observe that the kernel of the fundamental solution depends very strongly on the dimension n. 2. Embedding $\text{\bf C}^1$ into $\text{\bf H}_1$ Canad.J. Math. Vol. 47 (6)(1996), 1317-1328.Abstract: In this paper, we proved directly a theorem of Greiner in $n=1$. This result implies that the classical Mikhlin-Calderon-Zygmund calculus for the Principal value convolution operators on $C^1$ is, in a natural way, the limit of Laguerre calculus for principal value convolution operators on the Heisenberg group. 3. (Joint with Der-Chen Chang)) Estimates for the spectral projection operators of the sub-Laplacian on the Heisenberg group J. Analyse. Math Vol.71 (6)(1997), 313-347. Abstract: We use Laguerre calculus to find the $L^p$ spectrum of the pair $({\mathcal L}, T)$. Here ${\mathcal L}$ is the Kohn's sub-Laplacian on the Heisenberg group. We find the kernels for the spectrum projection operators and show that they are Mikhlin-Calderon-Zygmundoperators.Estimates for the projection operators in various spaces were deduced. 4. The explicit solution of the $\bar\partial$-Neumann problem in the non-isotropic Siegel Domain. Canad. J. Math. Vol.49 (6) (1997),1299-132.Abstract: In this paper, we solve the $\bar\partial$-Neumann problem on (0,q) forms, 0≤q≤n, in the strictly pseudoconvex non-isotropic Siegel domain. The metric we use is invariant under the action of the Heisenberg group on the domain. The fundamental solution of the related differential equation is derived via the Laguerre calculus. We obtain an explicit formula for the kernel of the Neumann operator. We also construct the solution of the corresponding heat equation and the fundamental solution of the Laplacian operator on the Heisenberg group. 5. (Joint with Der-Chen Chang) Applications of Laguerre calculus to Dirichlet problem of the Heisenberg Laplacian.Finite or infinite dimensional complex analysis, (Fukuoka, 1999), 47--53, Lecture Notes in Pure and Appl. Math., 214, Dekker, New York, 2000.Abstract: The purpose of this paper is to describe research we have been doing recently in an area of analysis lies at the confluence of two directions of research: the study of Laguerre calculus on the Heisenberg group, and the theory of subelliptic boundaryvalue problems. Here we intend only to outline part of the results we have obtained. 6. (Joint with Der-Chen Chang) Estimates for the powers of the sub-Laplacian on the non-isotropic Heisenberg group.J. Geom. Anal Vol.10(4) (2000), 653-678. Abstract: We apply the Laguerre calculus to obtain the explicit kernel for the fundamental solution of the powers and heat kernels of the Kohn's sub-Laplacian on the non-isotropic Heisenberg group. We then proved some estimates of these kernels in various spaces. 7. (Joint with Der-Chen Chang) An identity related to the Riesz transforms on the Heisenberg group.Complex Variables Theory Appl. Vol.40(6) (2000), 395--421. Abstract: Let be a real basis for the Heisenberg Lie algebra . In this paper, we calculate the explicit kernels of the Riesz transforms on the Heisenberg group Hn . Here is the sub-Laplacian operator. We show that for j = 1,2, … 2n where Rj 's are the regular Riesz transforms on . We also construct the “missing transform” such that in analogy of the classical result 8. (Joint with Der-Chen Chang) Some differential operators related to the sub-Laplacian on the non-isotropic Heisenberg group Math. Nachr. Vol. 221 (2001) 19-29. Abstract: Let ℒα = + iαT be the sub–Laplacian on the non–isotropic Heisenberg group Hn where Zj for j = 1, 2, …, n and T are a basis of the Lie algebra. We apply the Laguerre calculus to obtain the fundamental solution of the heat kernel exp{—sℒα}, the Schrödinger operator exp{—isℒα} and the operator + iαT. We also discuss some basic properties of the wave operator. 9. (Joint with Der-Chen Chang and Robert Gilbert), Bergman Projection and Weighted Holomorphic Functions,Operator Theory: Adavances and Applications, Vol. 143, 147-169, 2003.Abstract: In this paper, we prove the boundedness of the generalized Cesaro operators on Hardy and the generalized Bergman spaces and present a class of invariant subspace under the action of this operator. 10. (Joint with Der-Chen Chang and Peter C. Greiner) Sub-Riemannian Geometry and Subelliptic PDEs,Function Theory in Several Complex Variables, Editors: Carl H FitaGerald and Sheng Gong,Proceedings of a Satellite Conference to the ICM in Beijing 2002, 1-36, 2004. Abstract: the article is based on the lectures given by Der-Chen Chang and Peter C. Greiner a the Satellite Conferences of ICM 2002 on Geometric Function Theory in Several Complex Variables. We have surveyed the basic notion of the sub-Riemannian geometry on the Heisenberg group and the Martinet case. 11. (Joint with Der-Chen Chang) Hermit operator and Subelliptic Operators,Acta Math. Sin. (Engl. Ser.) Vol 21, no. 4, 803--818, (2005). 12. (Joint with Ovidiu Calin and Der-Chen Chang) Hermite Operator on the Heisenberg Group,Harmonic Analysis, Signal Processing and Complexity: Festschrift in Honor of the 60th Birthday of Carlos A. Berenstein, 37-54, 2005. 13. The fundamental solution and heat kernel of the twisted Laplacian on $\mathbb{R}^{2n}$.Communication in PDEs, Vol 31, no.7-9,1047--1069, {\bf 2006}. 14. (Joint with Ovidiu Calin and Der-Chen Chang) Fundamental Solutions for Hermite and Subelliptic Operators, J. Analyse. Math., Vol 100, 223--248, 2006. 15. (Joint with Der-Chen Chang and Peter C. Greiner) Laguerre Calculus on the Heisenberg group and Bessel-Fourier transform on ${\mathbb C}^n$,Sciences in China, Series A, Vol 49, no. 11, 1722--1739, 2006. 16. (Joint with M.W. Wong) The wave kernel of the twisted Laplacian on ${\mathbb C}^n$,Modern Trends in Pseudo-Differential Operators, 107--115, Oper. Theory Adv. Appl., Vol 172, 2007. 17. (Joint with M.W. Wong) The Heat Kernel and Green Functions of Sub-Laplacians on the Quaternion Heisenberg Group, Journal of Geometric Analysis, Vol 19, 191-210, 2009. 18. (Joint with Der-Chen Chang and Shu-Cheng Chang) Laguerre Calculus and Paneitz Operator on the Heisenberg group, Sci. China Ser. A , Vol 52 , No. 12, 2549-2966, 2009. 19. (Joint with Shu-Cheng Chang and Chin-Tung Wu) Subgradient Estimate and Liouville-type Theorems for the CR Heat Equation on Heisenberg groups,Asian Journal of Mathematics, Vol 14, Number 1, 41-72, 2010. 20. (Joint with Malcolm R. Adams) On Sub-Riemannian Geodesics Induced by the Engel Groups; Hamiltonian Equations, Mathematische Nachrichte, Volume 286, Issue 14-15, 1381–1406, 2013. 21 (Joint with Duy Nguyen and Qing Zhang), An Optimal Trading Rule Under A Switchable Mean-Reversion Model, Journal of Optimization Theory and Applications, Vol 161, 145-163, 2014 22. (Joint with Duy Nguyen and Qing Zhang) Stock Trading Rules under a Switchable Market, Mathematical Control and Related Fields, Vol 3, Number 2, 209-231, 2013. 23. (Joint with Shu-Cheng Chang and Ting-Jung Kuo) Yau's Gradient Estimate and Liouville Theorem for Positive Pseudoharmonic Functions in a Complete Pseudohermitian $(2n+1)$-manifold, Submitted to Communications in PDEs, October 2013. 24. (Joint with Der-Chen Chang and Shu-Cheng Chang) Calabi-Yau Theorem and Hodge-Laplacian Heat Equation in a Closed Strictly Pseudoconvex CR Manifold,Journal of Differential Geometry, Vol 97, 395-425, 2014.25. (Joint with Shu-Cheng Chang, Yen-Wen Fan and Chin-Tung Wu), Matrix Li-Yau-Hamilton Inequality for the CR Heat Equation in Pseudo-Hermitian (2n+1)-Manifolds, Mathematische Annalen, Online First, May 2014. Education Education: Ph.D. in Mathematics, University of Toronto, Canada M. Sc in Applied Mathematics, University of Victoria, Canada B. Sc in Mathematics, Lanzhou University, China Teaching Teaching: Teaching Schedule Fall 2018Math 4700 Ordinary Differential Equations Spring 2018Math 4720 Ordinary Differential Equations Math 2700 Introduction to Differential Equations Fall 2017Math 4700 Ordinary Differential Equations Math 3100 Introduction to Analysis - Sequences and Series Summer 2017Math 3200 Introduction to Advanced Mathematics Spring 2017Math 4720 Introduction to Partial Differential Equations Math 2260 Integral Calculus Fall 2016Math 4700 Ordinary Differential Equations Summer 2016Math 3200 Introduction to Advanced Mathematics Spring 2016Math 4720 Introduction to Partial Differential Equations Fall 2015Math 2260 Integral CalculusMath 4700 Ordinary Differential Equations Summer 2015Math 2700 Introduction to Differential Equations Spinger 2015Math 3100 Introduction to Analysis - Sequences and Series Fall 2014 Math 3200 Introduction to Advanced Mathematics Math 2500 Multivariable Calculus Summer 2014Math 3200 Introduction to Advanced Mathematics Spring 2014Math 4720 Introduction to Partial Differential EquationsMath 8150 Complex Analysis Fall 2013Math 3100 Introduction to Analysis - Sequences and Series Summer 2013Math 3200 Introduction to Advanced Mathematics Spring 2013Math 8110 Real Analysis II Fall 2012Math 2260 Integral CalculusMath 8100 Real Analysis Summer 2012Math 3200 Introduction to Advanced Mathematics Spring 2012Math 8770 Partial Differential Equations Fall 2011Math 2250 Differential Calculus Summer 2011Math 2500 Multivariable Calculus Spring 2011Math 5210/7210 Foundation of Geometry I I Fall 2010Math 4100/6100 Real AnalysisMath 5200/7200 Foundation of Geometry I Summer 2010Math 3200 Introduction to Advanced Mathematics Spring 2010Math 2500 Multivariable CalculusMath 2700 Elementary Differential Equations Fall 2009Math 2260 Integral Calculus Summer 2009Math 2700 Introduction to Differential Equations Spring 2009Math 2200 CalculusMath 8150 Complex Analysis Fall 2008Math 3100 Sequences and SeriesMath 2260 Integral Calculus Summer 2008Math 2700 Introduction to Differential Equations Spring 2008Math 4720/6720 Introduction to Partial Differential Equations and Distribution TheoryMath 2250 University Calculus Fall 2006 Math 5002/7002 Geometry for Elementary TeachersMath 2250 Calculus Summer 2006 Math 2700 Introduction to Differential Equations Spring 2006Math 4720/6720 Introduction to Partial Differential Equatoions and Fourier Series Fall 2005Math 2200 Introduction to Differential Calculus Math 8100 Real Analysis Summer 2005 Math 2700 Introduction to Differential Equations Spring 2005Math 5002 Geometry for Elementary TeachersFres 1010 The Joy of Discovering Mathematics Fall 2004Math 2200 Introduction to Differential CalculusMath 2210 Introduction to Integral Calculus Summer 2004Math 2700 Introduction to Differential Equations Spring 2004Math 3100 Introduction to Analysis: Sequences and Seires Fall 2003Math 2200 Introduction to Differential Calculus Math 8100 Real Analysis and Basic Functional Analysis Summer 2003Math 2700 Introduction to Differential Equations Spring 2003Math 8770 Introduction to Fourier analysis and PDE. Fres 1010 The Joy of Discovering Mathematics Fall 2002Math 2200 Introduction to Differential Calculus Summer 2002Math 2700 Introduction to Differential Equations Spring 2002Math 2200 Introduction to Differential Calculus Fall 2001Math 2200 Introduction to Differential Calculus Summer 2001Math 2200 Introduction to Differential Calculus Spring 2001Math 4720 Introduction to PDE and Boundary Value Problem. Fall 2000Math 8100 Real Analysis and Basic Functional Analysis Spring 2000Math 2700 Introduction to Differential Equations Fall 1999Math 2200 Introduction to Differential Calculus