3 papers
gr-qc2026
Coordinate- and spacetime-independent quantum physics
V. A. Emelyanov, D. Robertz
The concept of a particle is ambiguous in quantum field theory. It is generally agreed that particles depend not only on spacetime, but also on coordinates used to parametrise spac…
math.MG2025
Second-order prestress stability and third-order rigidity of polyhedral surfaces
Zeyuan He, Daniel Robertz
There has been a longstanding confusion on the proper definition of higher order rigidity and flexibility in geometric constraint systems. Recently, an energy-based formulation of…
math.CO2024
Construction of Toroidal Polyhedra corresponding to perfect Chains of wild Tetrahedra
Reymond Akpanya, Vanishree Krishna Kirekod, Alice C. Niemeyer +1
In 1957, Steinhaus proved that a chain of regular tetrahedra, meeting face-to-face and forming a closed loop does not exist. Over the years, various modifications of this statement…