collaborators

7 papers

hep-th2025

Quantum variational calculus on a lattice

Shahn Majid, Francisco Simão

We solve the long-standing problem of variational calculus on a noncommutative space or spacetime for a significant class of models with trivial jet bundle. Our approach entails a…

hep-th2025

Kaluza-Klein ansatz from Lorentzian quantum gravity on the fuzzy sphere

Chengcheng Liu, Shahn Majid

If Kaluza-Klein ideas were correct as an explanation of Yang-Mills and General Relativity on spacetime, the extra fibre geometry would have to be a sphere of constant size of the o…

math.QA2025

Quantum jet Hopf algebroids by cotwist

Xiao Han, Shahn Majid

We introduce a cotwist construction for Hopf algebroids that also entails cotwisting or `quantisation' of the base and which is dual to a previous twisting construction of P. Xu. W…

gr-qc2025

Klein-Gordon flow on FLRW spacetimes

Edwin Beggs, Shahn Majid

We study a new approach to generally covariant quantum mechanics applied in the case of an FLRW cosmological background. For positive spatial curvature we find a discrete series of…

math.QA2024

*-Hopf algebroids

Edwin Beggs, Xiao Han, Shahn Majid

We introduce a theory of -structures for bialgebroids and Hopf algebroids over a -algebra, defined in such a way that the relevant category of (co)modules is a bar category.…

gr-qc2024

Generally covariant quantum mechanics

Edwin Beggs, Shahn Majid

We obtain generally covariant operator-valued geodesic equations on a pseudo-Riemannian manifold as part of the construction of quantum geodesics on the algebra of diffe…