Browsing 2020 by Author "Bruschi, David Edward"

Now showing items 1-2 of 2

    • From Betti numbers to ℓ²-Betti numbers 

      [SNAP-2020-001-EN] Kammeyer, Holger; Sauer, Roman (Mathematisches Forschungsinstitut Oberwolfach, 2020-04-15)
      We provide a leisurely introduction to ℓ²-Betti numbers, which are topological invariants, by relating them to their much older cousins, Betti numbers. In the end we present an open research problem about ℓ²-Betti numbers.

    • Rotating needles, vibrating strings, and Fourier summation 

      [SNAP-2020-006-EN] Zahl, Joshua (Mathematisches Forschungsinstitut Oberwolfach, 2020-09-21)
      We give a brief survey of the connection between seemingly unrelated problems such as sets in the plane containing lines pointing in many directions, vibrating strings and drum heads, and a classical problem from Fourier analysis.