A picture of me.

Alex Townsend

Assistant Professor

Cornell University

townsend@cornell.edu

Malott 589

CV


Here are three images from my research:

Papers

  1. S. Olver, A. Townsend, and G. Vasil, A sparse spectral method on triangles, submitted, pdf

  2. Y. Nakatsukasa and A. Townsend, Error localization of best L1 polynomial approximants, submitted, pdf

  3. B. Beckermann and A. Townsend, Bounds on the singular values of matrices with displacement structure, to appear in SIAM Review, 2019.

  4. A. Horning and A. Townsend, FEAST for differential eigenvalue problems, submitted, pdf

  5. T. Shi and A. Townsend, On the numerical ranks of tensors, submitted, pdf

  6. K. N. Quinn, H. Wilber, A. Townsend, and J. P. Sethna, Chebyshev approximation and the global geometry of sloppy models, submitted.

  7. M. A. Gilles and A. Townsend, Continuous analogues of Krylov methods for differential operators, submitted, pdf.

  8. S. Olver, A. Townsend, and G. M. Vasil, Recurrence relations for orthogonal polynomials on a triangle, submitted, pdf.

  9. A. Townsend and H. Wilber, On the singular values of matrices with high displacement rank, Lin. Alg. Appl., 548 (2018), pp. 19-41. pdf

  10. D. Fortunato and A. Townsend, Fast Poisson solvers for spectral methods, submitted, pdf

  11. J. Słomka, A. Townsend, and J. Dunkel, Stokes' second problem and an Einstein-de Haas analogue effect in active fluids, to appear in Physical Review Fluids, pdf

  12. M. Udell and A. Townsend, Why are big data matrices approximately low rank?, to appear in SIMODS, pdf

  13. D. Ruiz-Antolin and A. Townsend, A nonuniform fast Fourier transform based on low rank approximation, SISC, 40 (2018), A529-A547. pdf

  14. B. Beckermann and A. Townsend, On the singular values of matrices with displacement structure, SIMAX, 38 (2017), pp. 1227-1248. pdf

  15. L. Demanet and A. Townsend, Stable extrapolation of analytic functions, Found. Comput. Math., (2016), pp. 1-35. pdf

  16. A. Townsend, M. Webb, and S. Olver, Fast polynomial transforms based on Toeplitz and Hankel matrices, Math. Comp., 87 (2018), pp. 1913-1934. pdf

  17. H. Wilber, A. Townsend, and G. B. Wright, Computing with functions in spherical and polar geometrices II. The disk, SISC, 39 (2017), C238-C262. pdf

  18. A. Townsend, Gaussian elimination corrects pivoting mistakes, submitted, pdf

  19. A. Townsend, H. Wilber, and G. B. Wright, Computing with functions in spherical and polar geometries I. The sphere, SISC, 38 (2016), C403-C425. pdf

  20. V. Noferini and A. Townsend, Numerical instability of resultant methods for multidimensional rootfinding, SINUM, 54 (2016), pp. 719-743. pdf

  21. N. Hale and A. Townsend, A fast FFT-based discrete Legendre transform, IMA Numer. Anal., 36 (2016), pp. 1670-1684. pdf

  22. A.Townsend, A fast analysis-based discrete Hankel transform using asymptotic expansions, SINUM, 53 (2015), pp. 1897-1917. pdf

  23. A. Townsend, The race for high order Gauss-Legendre quadrature, in SIAM News, March 2015. pdf

  24. A. Townsend, T. Trogdon, and S. Olver, Fast computation of Gauss quadrature nodes and weights on the whole real line, IMA Numer. Anal., 36 (2016), pp. 337-358. pdf.

  25. S. Olver and A. Townsend, A practical framework for infinite-dimensional linear algebra, in HPTCDL 2014, IEEE press, pp. 57-62. pdf

  26. A. Townsend and S. Olver, The automatic solution of partial differential equations using a global spectral method, J. Comput. Phys., 299, 2015, pp. 106-123. pdf

  27. N. Hale and A. Townsend, An algorithm for the convolution of Legendre series, SISC, 36 (2014), A1207-A1220. pdf

  28. A. Townsend and L. N. Trefethen, Continuous analogues of matrix factorizations, Proc. R. Soc. A., 471 (2015). pdf

  29. N. Hale and A. Townsend, A fast, simple, and stable Chebyshev--Legendre transform using an asymptotic formula, SISC, 36 (2014), pp. A148-A167. pdf

  30. S. Olver and A. Townsend, Fast inverse transform sampling in one and two dimensions, submitted. pdf

  31. Y. Nakatsukasa, V. Noferini, and A. Townsend, Computing the common zeros of two bivariate functions via Bezout resultants, Numerische Mathematik, 129 (2015), pp 181-209. pdf

  32. A. Townsend and L. N. Trefethen, An extension of Chebfun to two dimensions, SISC, 35 (2013), pp. C495-C518. pdf

  33. Y. Nakatsukasa, V. Noferini, and A. Townsend, Vector spaces of linearizations for matrix polynomials: A bivariate polynomial approach, SIMAX, 38 (2017), pp. 1-29. pdf

  34. A. Townsend and L. N. Trefethen, Gaussian elimination as an iterative algorithm, SIAM News, March 2013. pdf

  35. N. Hale and A. Townsend, Fast and accurate computation of Gauss--Legendre and Gauss--Jacobi quadrature nodes and weights, SISC, 35 (2013), pp. A652-A672. pdf

  36. S. Olver and A. Townsend, A fast and well-conditioned spectral method, SIAM Review, 55 (2013), pp. 462-489. pdf

  37. A. Townsend and H. Wendland, Multiscale analysis in Sobolev spaces on bounded domains with zero boundary values, IMA J. Numer. Anal., 33 (2013), pp. 1095-1114. pdf