2 papers
quant-ph2025
A Conjecture on Almost Flat SIC-POVMs
Ingemar Bengtsson, Markus Grassl
A well supported conjecture states that SIC-POVMs -- maximal sets of complex equiangular lines -- with anti-unitary symmetry give rise to an identity expressing some of its overlap…
gr-qc2025
Ultra-massive spacetimes in 2+1 dimensions with positive Λ
Ingemar Bengtsson, José M M Senovilla
We show that ultra-massive spacetimes exist also in 2 + 1 dimensions with a positive cosmological constant Λ > 0. They can be created through the collapse of a spherical null dust…