Publications

G. Yang, A. Onwunta, and D. An, Quantum differential equation solvers with low state preparation cost: Eliminating the time dependence in dissipative equations,  August 2025.

P.  Dondl,  A. Onwunta, L. Striet, and  S. Wojtowytsch, Convex-concave splitting for the Allen-Cahn equation leads to ε2-slow movement of interfaces, June 2025.

H. Antil, S. Dolgov, and A. Onwunta, Smoothed Moreau-Yosida tensor train approximation of state-constrained optimization problems under uncertainty, Numerical Linear Algebra with Applications, June 2025.

O. Akande, P.  Dondl, K. Gupta, A. Onwunta, and  S. Wojtowytsch, Momentum-based minimization of the Ginzburg-Landau functional on Euclidean spaces and graphs, January 2025.

H. Antil, S. Dolgov, and A. Onwunta, Tensor train solution to uncertain optimization problems with shared sparsity penalty,  November 2024.

D. An, A. Onwunta, and G. Yang, Fast-forwarding quantum algorithms for linear dissipative differential equations, October 2024.

A. Onwunta and C.W. Royer, Complexity analysis of regularization methods for implicitly constrained least-squares,  Journal of Scientific Computing, 2024. 

Y. Huang, Q. Wang,  A. Onwunta, and  B. Wang, Efficient score matching with deep equilibrium layers, International Conference on Learning Representations (ICLR), 2024.

V. Leplat, L. T. K. Hien, A. Onwunta, and N. Gillis, Deep nonnegative matrix factorization with beta divergences, Neural Computation, 2024.

H. Antil, H. C. Elman, A. Onwunta, and D. Verma, A deep neural network approach for parameterized PDEs and Bayesian inverse problems, Machine Learning: Science & Technology, 4 (3) 035015, 2023.

H. Antil, S. Dolgov, and A. Onwunta, TTRISK: Tensor train decomposition algorithm for risk-averse optimization, Numerical Linear Algebra with Applications, 2022, https://doi.org/10.1002/nla.2481.

H. Antil, T. S. Brown, R. Khatri,  A. Onwunta, D. Verma, and M. Warma, Optimal control, numerics and applications of fractional PDEs, Handbook of Numerical Analysis,  23, pp. 87-114, 2021.

P. Benner, S. Dolgov, A. Onwunta, and M. Stoll, Low-rank solution of an optimal control problem governed by random Navier-Stokes equations, International Journal for Numerical Methods in Fluids, pp. 1-26, 2020.

H. C. Elman and A. Onwunta, Reduced-order modeling for nonlinear Bayesian statistical inverse problems, 2020.

P. Benner, A. Onwunta, and M. Stoll, A low-rank inexact Newton-Krylov method for stochastic eigenvalue problems, Computational Methods in Applied Mathematics, 19 (1), pp. 5-22, 2019.

P. Benner, A. Onwunta, and M. Stoll, On the existence and uniqueness of the solution of a parabolic optimal control problem with uncertain inputs, 2018

P. Benner, S. Dolgov,   A. Onwunta, and M. Stoll, Low-rank solvers for unsteady Stokes-Brinkman optimal control problem with random data, Computer Methods in Applied Mechanics and Engineering, 304, pp. 26 - 54, 2016.

P. Benner, A. Onwunta, and M. Stoll, Block-diagonal preconditioning for optimal control problems constrained by PDEs with uncertain inputs, SIAM Journal on Matrix Analysis and Applications, 37 (2), pp. 491-518, 2016.

P. Benner, A. Onwunta, and M. Stoll, Low-rank solution of unsteady diffusion equations with  stochastic coefficients, SIAM/ASA Journal on Uncertainty Quantification, 3 (1), pp. 622 -649, 2015.

M. Lyra, A. Onwunta, and P. Winker,Threshold accepting for credit risk assessment and validation, Journal of Banking Regulation, 16 (2),  pp. 130 - 145, 2015.

M. Kalkbrener and A. Onwunta, Validating structural credit portfolio models, In D. Roesch, and H. Scheule (eds.),  Model Risk: Identification, Measurement and Management,  pp. 233 - 261, Risk Books, London, 2010.

A. Onwunta, Contributions to credit portfolio modeling and optimization, Peter Lang AG - International Academic Publishers, Frankfurt, Germany, 2011. 

A. Onwunta, Low-rank iterative solvers for large-scale stochastic Galerkin linear systems, Ph.D Thesis in Applied Mathematics, Max Planck Institute Magdeburg and Otto von Guericke University Magdeburg, Germany, 2016. 

A. Onwunta, On the regularity of refinable functions, Master's Thesis, University of Stellenbosch, South Africa, 2006.