arXiv subjects

Rainer Muehlhoff

Publications and source records attributed to Rainer Muehlhoff.

3 recordsLinked to original sources

arXiv2024

Chatbots im Schulunterricht: Wir testen das Fobizz-Tool zur automatischen Bewertung von Hausaufgaben

This study examines the AI-powered grading tool "AI Grading Assistant" by the German company Fobizz, designed to support teachers in evaluating and providing feedback on student assignments. Against the societal backdrop of an overburdened education system and rising expectations for artificial intelligence as a solution to these challenges, the investigation evaluates the tool's functional suitability through two test series. The results reveal significant shortcomings: The tool's numerical grades and qualitative feedback are often random and do not improve even when its suggestions are incorporated. The highest ratings are achievable only with texts generated by ChatGPT. False claims and nonsensical submissions frequently go undetected, while the implementation of some grading criteria is unreliable and opaque. Since these deficiencies stem from the inherent limitations of large language models (LLMs), fundamental improvements to this or similar tools are not immediately foreseeable. The study critiques the broader trend of adopting AI as a quick fix for systemic problems in education, concluding that Fobizz's marketing of the tool as an objective and time-saving solution is misleading and irresponsible. Finally, the study calls for systematic evaluation and subject-specific pedagogical scrutiny of the use of AI tools in educational contexts.

cs.CY↗

arXiv2011

Higher Spin Quantum Fields as Twisted Dirac Fields

We pursue the idea of constructing higher spin fields as solutions to twisted Dirac operators. As general results we find that twisted prenormally hyperbolic first order operators (such as the Dirac operator) on globally hyperbolic Lorentzian spacetime manifolds have unique advanced and retarded Green's functions and their Cauchy problem is well-posed. The space of compactly supported Cauchy data can be equipped with a naturally induced Hermitian but generally indefinite product, which is shown to be independent of the underlying choice of Cauchy hypersurface. As a special result, we study one particular example of twisted Dirac operator for Fermionic fields of higher spin. It allows a canonical Hermitian product on the spinor bundle, but the resulting product on the space of compactly supported Cauchy data fails positivity. Thus, it is shown that this construction does not allow quantization by forming a C*-algebra representation of the canonical anti-commutation relations in the well known fashion generalizing the spin 1/2 construction by Dimock (1982). This document is equipped with an introduction to the formalism of 2-spinors on curved spacetimes in an invariant fashion using abstract index notation.

math-ph↗

arXiv2011

Cauchy Problem and Green's Functions for First Order Differential Operators and Algebraic Quantization

Existence and uniqueness of advanced and retarded fundamental solutions (Green's functions) and of global solutions to the Cauchy problem is proved for a general class of first order linear differential operators on vector bundles over globally hyperbolic Lorentzian manifolds. This is a core ingredient to CAR-/CCR-algebraic constructions of quantum field theories on curved spacetimes, particularly for higher spin field equations.

math-ph↗