Sreeram Shankar profile photo

Sreeram Shankar

Computational Mathematics and Scientific Computing

I am a researcher at the Oden Institute and an undergraduate at the Cockrell School of Engineering focused on computational and numerical differential equations. I develop and analyze numerical methods for ordinary and partial differential equations, with work spanning time integration, spatial discretization, and open-source implementation. I study time integration techniques that preserve mathematical and physical structure (such as stiffness, geometric preservation, and efficiency), with interests in fully implicit, stabilized, and IMEX general linear methods (RKs and LMMs) along with matrix-function and specialized methods. I additionally focus on spatial discretization such as isogeometric analysis, finite elements, finite volume, spectral, and other Galerkin methods, guided by the mathematical and numerical structure of the underlying models. I implement these methods in open-source software and am also interested in numerical linear algebra, modern techniques of scientific computing (scientific machine learning, reduced order modeling), and applications of these techniques to real problems.

News

Recent updates on papers, talks, and related work.
  • MIISO preprint available

    MIISO: Modal Integrators for Isogeometric Stabilization of Outliers is available on arXiv and currently in review in Applied Numerical Mathematics. It introduces a new family of time integration methods based on non-holomorphic blends of Padé approximants in an exponential Rosenbrock–Krylov scheme, targeting the outlier problem in isogeometric analysis without requiring assembly.

    arXiv:2609.25087

  • FerriteCon 2026

    Gave a talk at FerriteCon 2026 at TU Braunschweig covering the basics of isogeometric analysis and introducing FerriteIGA.jl to the Ferrite and Julia ecosystem ahead of its registration as a package.

Research

Problems and research I am currently pursuing. Advised by Jesse Chan at the Oden Institute at UT Austin.

Stabilized RK methods for diffusive problems

Looking into stabilized Runge–Kutta methods based on orthogonal polynomials, including standard and shifted Runge–Kutta Chebyshev, Legendre, and general Gegenbauer schemes, for efficient simulation of diffusion-dominated problems. The work is based on Trixi.jl and builds on implementations I contributed into OrdinaryDiffEq.jl. Focused on efficiency analysis and exploring specialized schemes for this regime.

MIISO: Modal integrators for Isogeometric Stabilization of Outliers

Developed a new class of numerical ODE methods for isogeometric analysis that target the spline space outlier problem in structural simulations. The methods are based on non-holormphic blends of Padé approximants of the exponential function and form a family of modified exponential Rosenbrock–Krylov schemes, called MIISO, constructed matrix-free for efficient implementation and backed by rigorous theoretical proofs. Available on arXiv and currently in review in Computer Methods in Applied Mechanics and Engineering.

arXiv:2609.25087

Projects

Numerical testbeds and software written to study specific discretizations, solvers, and model behavior.
2D Multigrid Cycle Analyzer
2D Multigrid Cycle Analyzer

A Julia-based numerical laboratory for studying geometric multigrid cycle behavior, smoother performance, residual decay, and FFT-resolved spectral effects in 2D finite-difference Poisson problems.

Stochastic Chemical Dynamics Testbed
Stochastic Chemical Dynamics Testbed

A controlled numerical framework for SSA, CLE, and solver comparison, built to study how modeling, discretization, and randomness architecture shape stochastic chemical dynamics.

Contributions

Open-source contributions to Julia packages in numerical methods and scientific computing.
  • Julia package for fully implicit Runge–Kutta methods, expanding on SciML's OrdinaryDiffEq.jl. Plans to expand this to custom collocation methods for expermentation and learning uses

  • Contributor to SciML's differential equation ecosystem.

    • Arbitrary-order Gauss–Legendre FIRK methods with further improvements
    • Monotone Runge–Kutta Chebyshev methods
    • Stabilized explicit Runge–Kutta–Legendre and Gegenbauer supertimestepping
    • HHT/Generalized-α methods for structural dynamics

Focuses and Interests

Research focuses and interests within computational mathematics, numerical analysis, and scientific computing.

Functional Analysis

Approximation Theory

Stiffness and Geometric Preservation

Nonlinear Hyperbolic PDEs and Shocks

Elliptic PDEs

Parabolic PDEs

Integro-Differential Equations

Initial Value Problems

Finite Element Methods