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Hybrid Risk Processes: A Versatile Framework for Modern Ruin Problems
Oscar Peralta, Habacuq Vallejo
https://arxiv.org/abs/2506.23685 https://

Hybrid Risk Processes: A Versatile Framework for Modern Ruin Problems
We introduce the hybrid risk process, constructed via a time-change transformation applied to the solution of a hybrid stochastic differential equation. The framework covers several modern ruin settings, incorporating features like Markov-modulation and reserve-dependent parameters through an interdependent structure where the surplus level influences the dynamics of the background environment. The approach lets us define and analyze the Generalized Omega ruin model, a novel definition of insol…

Quantum Fisher information as a witness of non-Markovianity and criticality in the spin-boson model
Daniele Parlato, Grazia Di Bello, Fabrizio Pavan, Giulio De Filippis, Carmine Antonio Perroni
https://arxiv.org/abs/2508.16413

Quantum Fisher information as a witness of non-Markovianity and criticality in the spin-boson model
The quantum Fisher information, the quantum analogue of the classical Fisher information, is a central quantity in quantum metrology and quantum sensing because of its connection to parameter estimation and fidelity susceptibility. Using numerically exact methods applied to a paradigmatic open quantum system, the spin-boson model, we calculate both static and dynamical quantum Fisher information matrix elements with respect to spin-bath couplings and magnetic field strengths. As the spin-bath i…

Boundary integral equation analysis for spheroidal suspensions
Leo Crowder, Tianyue Li, Eduardo Corona, Shravan Veerapaneni
https://arxiv.org/abs/2506.20809

Boundary integral equation analysis for spheroidal suspensions
In this work, we provide a fast, spectrally accurate method for the evaluation of boundary integral operators (BIOs) on a suspension of prolate and oblate spheroids. We first derive formulas for the standard layer potential operators for the Laplace equation applied to an expansion of the integral densities in the appropriate spheroidal harmonic basis. These then lead to analytical expressions in solid harmonics that allow spectrally accurate evaluation of near-field particle interactions. Fina…