arXiv subjects

Matthias Kaiser

Publications and source records attributed to Matthias Kaiser.

4 recordsLinked to original sources

arXiv2026

Challenges in the simulation of enzymatic transition states with emerging multireference character

Highly successful drugs, such as transition-state inhibitors, were designed by mimicking the precise geometry of enzymatic transition states, a strategy that requires quantum chemistry accurate enough to specify molecular structure at sub-\AA\ resolution. A central challenge during such a quantum chemistry simulation is that classical single-reference method can deviate substantially from the exact energy at strongly correlated transition states. We study the breakdown due to multireference character by studying a model system with a multireference transition state. In this work we present a proprietary PexMachina solver which reproduces the exact ground-state energy throughout the transition state scan, while single-reference methods struggle for certain geometries to achieve chemical accuracy.

physics.chem-ph↗

arXiv2025

A 'Turtle Model' of Food System Transformations: Embracing Citizens' Diverse Values and Knowledge in Change Processes

We explore the challenges and opportunities of transitioning towards sustainable food systems through the lens of democratic food governance fostering inclusive and systemic transformation. Drawing on concepts of wicked problems and systems thinking, we propose a theory of change represented as a 'turtle model' that embraces the diversity of citizens' values and knowledge to highlight multiple avenues of transformation. As quadruple helix innovation and governance hubs, cities can be hotspots for food system transformations. We illustrate this for Dublin, Ireland, where local citizens' value-based food identities were galvanized to activate ecological awareness and promote sustainable seafood consumption. Within this democratic food governance framework, approaches such as open science, transdisciplinarity, and citizen engagement are fit-for-purpose to engage diverse food actors from government, industry, academia, and civil society in shared dialogue and action to transform food systems.

econ.TH↗

arXiv2021

Models and numbers: Representing the world or imposing order?

We argue for a foundational epistemic claim and a hypothesis about the production and uses of mathematical epidemiological models, exploring the consequences for our political and socio-economic lives. First, in order to make the best use of scientific models, we need to understand why models are not truly representational of our world, but are already pitched towards various uses. Second, we need to understand the implicit power relations in numbers and models in public policy, and, thus, the implications for good governance if numbers and models are used as the exclusive drivers of decision making.

cs.CY↗

arXiv2021

Should policy makers trust composite indices? A commentary on the pitfalls of inappropriate indices for policy formation

This paper critically discusses the use and merits of global indices, in particular, the Global Health Security Index or GHSI (Cameron et 2019) in times of an imminent crisis, like the current pandemic. The index ranked 195 countries according to their expected preparedness in case of a pandemic or other biological threat. The Covid-19 pandemic provides the background to compare each country's predicted performance from the GHSI with the actual performance. In general, there is an inverted relation between predicted versus actual performance, i.e. the predicted top performers are among those that are the worst hit. Obviously, this reflects poorly on the potential policy uses of the index in imminent crisis management. The paper also uses two different data sets, one from the Worldmeter on the spread of the Covid-19 pandemics, and the other one from the INGSA policy tracker, to make comparisons between the actual introduction of pandemic response policies and the corresponding death rate in 29 selected countries.

cs.CY↗