Tootfinder

Positive Geometry of Polytopes and Polypols
Simon Telen
https://arxiv.org/abs/2506.05510 https://arxiv.org/pdf/2506.05510

Positive Geometry of Polytopes and Polypols
These are lecture notes supporting a minicourse taught at the Summer School in Total Positivity and Quantum Field Theory at CMSA Harvard in June 2025. We give an introduction to positive geometries and their canonical forms. We present the original definition by Arkani-Hamed, Bai and Lam, and a more recent definition suggested by work of Brown and Dupont. We compute canonical forms of convex polytopes and of quasi-regular polypols, which are nonlinear generalizations of polygons in the plane. T…

I've really enjoyed this miniseries on Houdini in case anyone is looking for something to listen to:
https://econtwitter.net/@TimHarford/114238312210225412

A semi-smooth Newton method for magnetic field problems with hysteresis
Herbert Egger, Felix Engertsberger
https://arxiv.org/abs/2506.01499 https://…

A semi-smooth Newton method for magnetic field problems with hysteresis
Ferromagnetic materials exhibit anisotropy, saturation, and hysteresis. We here study the incorporation of an incremental vector hysteresis model representing such complex behavior into nonlinear magnetic field problems both, from a theoretical and a numerical point of view. We show that the hysteresis operators, relating magnetic fields and fluxes at every material point, are strongly monotone and Lipschitz continuous. This allows to ensure well-posedness of the corresponding magnetic field pr…

On his 2025 inaugural date #DJT signed an executive order titled "Ending The Weaponization Of Government.”
...and every #MAGA accusation is instead a confession, as the troops from federal agencies under his aegis go after any perceived political enemy he sees.
This week alone: * DJT

Trump's DOJ Brings Baseless Charges Against Lamonica McIver
What's really behind the Justice Department's baseless charges against Rep. McIver?

David Brooks: "What’s Happening Is Not Normal. America Needs an Uprising That Is Not Normal"
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It’s time for a comprehensive national civic uprising. It’s time for Americans in universities, law, business, nonprofits and the scientific community, and civil servants and beyond to form one coordinated mass movement. Trump is about power. The only way he’s going to be stopped is if he’s confronted by some movement that possesses rival power."
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Opinion | What’s Happening Is Not Normal. America Needs an Uprising That Is Not Normal.
It will take a concerted effort by every sector of our society to respond to Trumpism’s threat.

I've really enjoyed this miniseries on Houdini in case anyone is looking for something to listen to:
https://econtwitter.net/@TimHarford/114238312210225412