Tootfinder

Ahh bliss. For the first time since Mum went into hospital just over 2wks ago I've actually slept through the night for nearly 9hrs! Sleep fell to pieces initially, no more than 2hrs at a time for several nights which was murder, esp as I still had to go to work, go to hosp, speak to docs etc. I'm back on the magnesium bisglycinate and have chucked in valerian again too for the time being. Added now we know the plan for her and have certainty that she's not coming home so my brai…

Mean field social optimization: feedback person-by-person optimality and the dynamic programming equation
Minyi Huang, Shuenn-Jyi Sheu, Li-Hsien Sun
https://arxiv.org/abs/2508.14236

Mean field social optimization: feedback person-by-person optimality and the dynamic programming equation
We consider mean field social optimization in nonlinear diffusion models. By dynamic programming with a representative agent employing cooperative optimizer selection, we derive a new Hamilton--Jacobi--Bellman (HJB) equation to be called the master equation of the value function. Under some regularity conditions, we establish $ε$-person-by-person optimality of the master equation-based control laws, which may be viewed as a necessary condition for nearly attaining the social optimum. A major c…

The Interpolation Constraint in the RV Analysis of M-Dwarfs Using Empirical Templates
Dhvani Doshi, Nicolas B. Cowan, \'Etienne Artigau, Ren\'e Doyon, Andr\'e M. Silva, Khaled Al Moulla, Yashar Hezaveh
https://arxiv.org/abs/2508.10980

The Interpolation Constraint in the RV Analysis of M-Dwarfs Using Empirical Templates
Precise radial velocity (pRV) measurements of M-dwarfs in the near-infrared (NIR) rely on empirical templates due to the lack of accurate stellar spectral models in this regime. Templates are assumed to approximate the true spectrum when constructed from many observations or in the high signal-to-noise limit. We develop a numerical simulation that generates SPIRou-like pRV observations from PHOENIX spectra, constructs empirical templates, and estimates radial velocities. This simulation solely …

In Zeiten von Fake News und Klimawandel-Leugnern kann man nur froh sein, dass es noch aufrechte Wissenschaftler gibt, die sich nicht mundtot machen lassen.
https://youtube.com/watch?v=7-h0zKgJkBk&si=rbXw3ad8twO7jUQO

Myopic Optimality: why reinforcement learning portfolio management strategies lose money
Yuming Ma
https://arxiv.org/abs/2509.12764 https://arxiv.org/pdf/2…

Myopic Optimality: why reinforcement learning portfolio management strategies lose money
Myopic optimization (MO) outperforms reinforcement learning (RL) in portfolio management: RL yields lower or negative returns, higher variance, larger costs, heavier CVaR, lower profitability, and greater model risk. We model execution/liquidation frictions with mark-to-market accounting. Using Malliavin calculus (Clark-Ocone/BEL), we derive policy gradients and risk shadow price, unifying HJB and KKT. This gives dual gap and convergence results: geometric MO vs. RL floors. We quantify phantom …

Achieving Optimal Performance-Cost Trade-Off in Hierarchical Cell-Free Massive MIMO
Wei Jiang, Hans D Schotten
https://arxiv.org/abs/2508.20704 https://arx…

Achieving Optimal Performance-Cost Trade-Off in Hierarchical Cell-Free Massive MIMO
Cell-free (CF) massive MIMO offers uniform service via distributed access points (APs), which impose high deployment costs. A novel design called hierarchical cell-free (HCF) addresses this problem by replacing some APs with a central base station, thereby lowering the costs of fronthaul network (wireless sites and fiber cables) while preserving performance. To identify the optimal uplink configuration in HCF massive MIMO, this paper provides the first comprehensive analysis, benchmarking it ag…

The hyperbolically symmetric black hole
L. Herrera, L. Witten
https://arxiv.org/abs/2509.02621 https://arxiv.org/pdf/2509.02621

The hyperbolically symmetric black hole
We describe some properties of the hyperbolically symmetric black hole (hereafter referred to as the $HSBH$) proposed a few years ago. We start by explaining the main motivation behind such an idea, and we determine the main differences between this scenario and the classical black hole (hereafter referred to as the $CBH$) scenario. Particularly important are the facts that, in the $HSBH$ scenario, (i) test particles in the region inside the horizon experience a repulsive force that prevents th…

Error estimates for finite-dimensional approximations of Hamilton-Jacobi-Bellman equations on the Wasserstein space
Samuel Daudin, Joe Jackson, Benjamin Seeger
https://arxiv.org/abs/2510.02652

Error estimates for finite-dimensional approximations of Hamilton-Jacobi-Bellman equations on the Wasserstein space
In this paper, we study a Hamilton-Jacobi-Bellman (HJB) equation set on the Wasserstein space $\mathcal{P}_2(\mathbb{R}^d)$, with a second order term arising from a purely common noise. We do not assume that the Hamiltonian is convex in the momentum variable, which means that we cannot rely on representation formulas coming from mean field control. In this setting, Gangbo, Mayorga, and Święch showed via viscosity solutions methods that the HJB equation on $\mathcal{P}_2(\mathbb{R}^d)$ can be …

Optical and near-infrared nebular-phase spectroscopy of SN 2024ggi: constraints on the structure of the inner ejecta, progenitor mass, and dust
Emilio Hueichap\'an, R\'egis Cartier, Jose L. Prieto, Carlos Contreras, Aleksandar Cikota, Thallis Pessi, Franz E. Bauer, Giuliano Pignata
https://arxiv.org/abs/2508.02656

Optical and near-infrared nebular-phase spectroscopy of SN 2024ggi: constraints on the structure of the inner ejecta, progenitor mass, and dust
We present optical and near-infrared (NIR) spectroscopic observations of the nearby Type II supernova SN\,2024ggi from 250 and 420 days after the explosion. Comparing the evolution of the [\ion{O}{1}] at 6300, 6363 \textÅ doublet normalized to the continuum with spectral models from the literature, we estimate a progenitor star zero-age main-sequence mass ($M_{\mathrm{ZAMS}}$) of $\approx 14$ M$_\odot$. This value is consistent with $M_{\mathrm{ZAMS}}$ reported in the literature from independe…

A semi-Lagrangian method for solving state constraint Mean Field Games in Macroeconomics
Fabio Camilli, Qing Tang, Yong-shen Zhou
https://arxiv.org/abs/2510.00768 https://

A semi-Lagrangian method for solving state constraint Mean Field Games in Macroeconomics
We study continuous-time heterogeneous agent models cast as Mean Field Games, in the Aiyagari-Bewley-Huggett framework. The model couples a Hamilton-Jacobi-Bellman equation for individual optimization with a Fokker-Planck-Kolmogorov equation for the wealth distribution. We establish a comparison principle for constrained viscosity solutions of the HJB equation and propose a semi-Lagrangian (SL) scheme for its numerical solution, proving convergence via the Barles-Souganidis method. A policy ite…