3 papers
gr-qc2026
Spacelike reduction of the gravitational topological terms and associated helicity densities
Hongxi Huang, Jiang Long, Gan Zhao +1
Helicity in gravity is a multifaceted concept, and several inequivalent definitions exist in the literature. In this work, we reduce the topological Pontryagin and Nieh-Yan terms t…
hep-th2025
Electromagnetic helicity flux density for radiative systems
Zhen-Yu Heng, Jiang Long, Run-Ze Yu +1
We show that the helicity flux density is distinguished from magnetic helicity by analysing Hopf solitons. The electromagnetic (EM) helicity flux and the magnetic helicity are Cher…
gr-qc2024
Gravitational helicity flux density from two-body systems
Jiang Long, Run-Ze Yu
The helicity flux density is a novel quantity which characterizes the angle-dependence of the helicity of radiative gravitons and it may be tested by gravitational wave experiments…