Barbara Wohlmuth Delivers Inaugural J. Tinsley Oden Lecture

On April 15, 2025, Barbara Wohlmuth, Chair of Numerical Mathematics at the Technical University of Munich (TUM), delivered the inaugural J. Tinsley Oden Distinguished Lecture at the Oden Institute for Computational Engineering and Sciences. Titled “Mathematical Challenges in Computational Science and Engineering: From Modeling through Analysis to Simulation,” the talk was a tour-de-force in numerical analysis - a field advanced in no small part by Wohlmuth and her longtime friend and collaborator, Dr. Oden. 

Wohlmuth’s lecture focused on numerical analysis’ applications across fields, interspersed by memories of her work with Dr. Oden and faculty members across the Institute. Her talk covered fractional time derivatives, which hold applications in thermoplastic polymer research. “These problems are hugely problematic mathematically,” Wohlmuth shared. “None of the standard rules, like chain and product rule, hold true for these operators.” When these rules break down, advancements in numerical analysis - including kernel compression techniques, supported by the AAA algorithm, enable us to create models for these challenging systems. 

Wohlmuth also highlighted the implications of these techniques on time fractional PDEs. She likened fractional time models to a group of mismatched hikers: one team starts off with a burst of energy, racing ahead only to tire out near the summit, while the other begins slowly and steadily, gradually gaining momentum to finish strong. This dynamic, she explained, mirrors how memory effects in fractional time derivatives influence the pace and behavior of evolving systems.

The principles of this work can also be applied to equations that vary over space – which  is critical to our understanding of renewable energy and harnessing the power of wind – especially when we consider fringe, extreme events when optimizing turbines or modelling extreme weather events. 

Concluding with a paper borne of her final collaboration with Dr. Oden, Wohlmuth highlighted their research on tumor growth dynamics through an Agent-Based Model (ABM). The work focused on the combined effects of two drugs aimed at inhibiting distinct stages of tumor progression—proliferation and angiogenesis.

A hallmark of many of their collaborations, the work was both rigorous and lighthearted. Wohlmuth fondly recalled how Tinsley ensured that their time together was both productive and memorable. “Tinsley got us tickets to a UT game and took us to a bar,” she shared. “The next day – 6am on a Sunday morning, I woke up to a call from him asking why we weren’t in the office.” This memory of Dr. Oden’s ever-curious, friendly spirit was shared across the Avaya Auditorium – by faculty, staff, and students alike. 

At the heart of the research was an exploration of how the vascular endothelial growth factor (VEGF), which is secreted by tumors to promote angiogenesis, contributes to tumor survival. Angiogenesis is essential for establishing a nutrient supply to the tumor by increasing vascular density, which in turn allows the tumor to grow more rapidly. However, the team’s ABM for tumor growth predicted that a combination of two drugs—one inhibiting proliferation and the other blocking angiogenesis—would have a synergistic effect, leading to significant tumor cell death.

Barbara Wohlmuth’s lecture not only celebrated the lasting impact of her collaborations with Dr. Oden but also showcased the transformative role of interdisciplinary research in solving complex scientific challenges. From fractional time derivatives to tumor growth modeling, her work bridges theoretical innovation with practical applications. As the inaugural speaker of the J.Tinsley Oden Distinguished Lecture, Wohlmuth’s contributions continue to inspire and shape the future of computational science and engineering.

The J. Tinsley Oden Lecture honors the contributions of Dr. J. Tinsley Oden, who passed away on August 27, 2023. This annual event brings together the Oden Institute community in an interdisciplinary forum of the kind that was close to Tinsley's heart. Each year, the lecture will be delivered by an outstanding individual who is selected for their contributions to computational science engineering, and mathematics.