1. Borsuk’s partition conjecture

   • Chuanming Zong

   Original Paper 21 July 2021 Pages: 185 - 201

2. Classical and variational Poisson cohomology

   • Bojko Bakalov
   • Alberto De Sole
   • Veronica Vignoli

   Original Paper 09 August 2021 Pages: 203 - 246

3. Grothendieck spaces: the landscape and perspectives

   • Manuel González
   • Tomasz Kania

   Original Paper 22 September 2021 Pages: 247 - 313