arXiv subjects

Eve Cheng

Publications and source records attributed to Eve Cheng.

3 recordsLinked to original sources

arXiv2024

Complex hypergraph analysis of Australian MPs' professional connections, 1947-2019

We propose a suit of methods to analyse the professional networks of MPs, showing how to analyse weak-tie connections between legislators and the connections between background charactersitic attributes. Applied to a novel dataset on the backgrounds of Australian MPs in the Australian Labor Party and the Liberal Party of Australia (1947-2019), we show that our approach can help to describe and explain the decline in working-class and trade unionist MPs from the Labor Party, the homogeneous elitism of the mid-20 century Liberal Party, and the increasing similarity of both parties' professional networks, occuring in the period of party cartellisation from the 1980s onward. Our paper's finding show that our method has clear potential for broader applications in the study of political representation, diversity, and elite political networks.

cs.SI↗

arXiv2023

Topological analysis of the complex SSH model using the quantum geometric tensor

This paper presents two methods for topological analysis of the complex Hermitian Su-Schrieffer-Heeger (SSH) model using the quantum geometric tensor: Berry phase and topological data analysis. We demonstrate how both methods can effectively generate topological phase diagrams for the model, revealing two distinct regions based on the relative magnitudes of the parameters $|v|$ and $|w|$. Specifically, when $|v| > |w|$, the system is found to be topologically trivial, whereas for $|v| < |w|$, it exhibits topologically non-trivial behavior. Our results contribute to building the groundwork for topological analysis of more complicated SSH-type models.

cond-mat.str-el↗

arXiv2021

Ground-state energy of quasi-free positrons in non-polar fluids

We have calculated the background energy ($V_0$) for positrons in noble gases with an \emph{ab initio} potential and the Wigner-Seitz (WS) ansatz. {\col In contrast to the general pseudo-potential approach, we have used accurate \emph{ab initio} potentials for the positron-atom interaction.} The ansatz includes an assumed form of the potential, resulting from an average over fluid atoms, and we propose four different options for this. By comparing the different options to literature data for effective electron number ($Z_{\text{eff}}$), we find that agreement can be obtained for light elements, but fails for heavy elements. We suspect that the strong polarizability of the heavy elements makes the simple potential averaging, as assumed in the Wigner-Seitz model, insufficient to fit the measurements without also making use of pseudo-potentials. We also raise our suspicion that the comparison of annihiliation rates between ground-state calculations and experimental values is not appropriate. Furthermore, the congruence of $V_0$ to $Z_{\text{eff}}$ values predicted by a contact potential approximation appears to be invalidated by our results.

physics.chem-ph↗