arXiv subjects

Lorenz Hartmann

Publications and source records attributed to Lorenz Hartmann.

3 recordsLinked to original sources

arXiv2026

Dependence uncertainty: a decision-theoretic approach

We propose and axiomatize preferences on a product state space in light of uncertainty regarding the dependency of different payoff-relevant factors. Dependence structures allow to decompose probabilities and allow to pin down behavior towards dependence. The degree of dependence aversion is measured by dependence premia that are compatible with the encompassed MEU and smooth preferences on the dependence uncertainty set. A separation axiom clarifies when uncertainty about dependence breaks down and the decision maker treats factors as independent, making dependence neglect testable. We describe the dependence uncertainty set as a convex polytope and characterize their extreme points as maximizers of divergences. The model and its tools are applied to simple examples on climate change, insurance, and portfolio choice.

econ.TH↗

arXiv2003

Weak Coherent State Path Integrals

Weak coherent states share many properties of the usual coherent states, but do not admit a resolution of unity expressed in terms of a local integral. They arise e.g. in the case that a group acts on an inadmissible fiducial vector. Motivated by the recent Affine Quantum Gravity Program, the present article studies the path integral representation of the affine weak coherent state matrix elements of the unitary time-evolution operator. Since weak coherent states do not admit a resolution of unity, it is clear that the standard way of constructing a path integral, by time slicing, is predestined to fail. Instead a well-defined path integral with Wiener measure, based on a continuous-time regularization, is used to approach this problem. The dynamics is rigorously established for linear Hamiltonians, and the difficulties presented by more general Hamiltonians are addressed.

hep-th↗

arXiv2003

Weak Coherent States and their Path Integrals

Weak coherent states share many properties of the usual coherent states, but do not admit a resolution of unity expressed in terms of a local integral. They arise e.g. in the case that a group acts on an inadmissible fiducial vector. Motivated by the recent Affine Quantum Gravity Program, the present work studies the path integral representation of the affine weak coherent state matrix elements of the unitary time-evolution operator. Since weak coherent states do not admit a resolution of unity, it is clear that the standard way of constructing a path integral, by time slicing, is predestined to fail. Instead, a well-defined path integral with Wiener measure, based on a continuous-time regularization, is used to approach this problem. The dynamics is rigorously established for linear Hamiltonians, and the difficulties presented by more general Hamiltonians are addressed.

hep-th↗