2 citations · 9 across the 6 of their papers we have counts for
4 papers · 1 filter
Degree of arbitrariness directly from moving frames
Ziyang Hu
For physical theories, the degree of arbitrariness of a system is of great importance, and is often closely linked to the concept of degree of freedom, and for most systems this nu…
A framework for structure-preserving submersions and some theorems in relativistic flows
Ziyang Hu
In this paper we first propose a framework of structure-preserving submersions, which generalises the concept of a Riemannian submersion, and dualises the concept of subgeometry, o…
On the General Problem of Structure-Preserving Submersions
Ziyang Hu
In this paper we give a general geometrical framework for working with problems that can be described as a structure-preserving submersion defined on a suitable space with a geomet…
A modern view of the classical Herglotz-Noether theorem
Ziyang Hu
In this paper we give a new proof, valid for all dimensions, of the classical Herglotz-Noether theorem that all rotational shear-free and expansion-free flows (rotational Born-rigi…