Tootfinder

Another #hiking story is online! No mountains this time but along the shores of the river #Mangfall .
Tough to photograph on such a day. In autumn - with some fog - it must be great. But we really had a great day there!
See more of it:

"Turning closed coal mines into solar farms could power a country the size of Germany, report finds"
#Germany #CoalMine #SolarPower

Report reveals huge solar power potential of abandoned coal mines
“The same ground that powered the industrial era can help power the climate solutions we now urgently need,” analysts say of the 300 GW solution.

The Szczarba map and the cubical cobar construction
Matthias Franz
https://arxiv.org/abs/2507.01669 https://arxiv.org/pdf/2507.01669

The Szczarba map and the cubical cobar construction
We consider a twisting function from a 1-reduced simplicial set $X$ to a simplicial group $G$. We prove in detail that the associated Szczarba operators induce a simplicial map from the triangulation of the cubical cobar construction of $X$ to $G$. This confirms a result due to Minichiello-Rivera-Zeinalian and gives, as pointed out by these authors, a conceptual proof of the fact that the dga map $Ω\,C(X) \to C(G)$ induced by Szczarba's twisting cochain is comultiplicative.

Experimental demonstration of attosecond hard X-ray pulses
Ichiro Inoue, River Robles, Aliaksei Halavanau, Veronica Guo, Thomas M. Linker Andrei Benediktovitch, Stasis Chuchurka, Matthew H. Seaberg, Yanwen Sun, Diling Zhu, David Cesar, Yuantao Ding, Vincent Esposito, Paris Franz, Nicholas S. Sudar, Zhen Zhang, Taito Osaka, Gota Yamaguchi, Yasuhisa Sano, Kazuto Yamauchi, Jumpei Yamada, Uwe Bergmann, Matthias F. Kling, Claudio Pellegrini, Makina Yabashi, Nina Rohringer, Takahiro Sato, Ag…

Experimental demonstration of attosecond hard X-ray pulses
We present the first direct experimental confirmation of attosecond pulse generation in the hard X-ray regime with a free-electron laser. Our experiment is based on measurements of a nonlinear optical phenomenon known as amplified spontaneous emission (ASE) from 3d transition metals. By analyzing the yield of the collective X-ray fluorescence induced by ultrashort pulses at the Linac Coherent Light Source, we identify the generation of attosecond pulses and shot-to-shot fluctuations in their du…