arXiv subjects

Yuhua Yao

Publications and source records attributed to Yuhua Yao.

3 recordsLinked to original sources

arXiv2026

Spectral Softenings, Composition Bump, and Anisotropy Transition: A Consistent Picture of Cosmic-Ray Origin Below the Knee

Recent DAMPE measurements of individual cosmic-ray components, including carbon, oxygen, and iron, reveal distinct spectral softenings below the knee. The energy spectrum, mass composition, and anisotropy together provide key probes of cosmic-ray origin and propagation. By incorporating the individual elemental spectra reported by DAMPE, we derive a more complete $\langle \ln A\rangle$ distribution, which smoothly connects to the higher-energy $\langle \ln A\rangle$ measurements from LHAASO and exhibits a pronounced bump-like feature. This feature indicates a transition from the conventional Galactic cosmic ray source population to a nearby-source-dominated regime. We show that a spatially dependent propagation model with a nearby-source contribution can consistently reproduce the observed spectra, mass composition, and anisotropy. This suggests a unified picture in which Galactic cosmic rays below the knee arise from multiple source populations jointly constrained by these observables. Leveraging the precise component-resolved spectra from DAMPE, we further predict the transition energies in the anisotropy phase and amplitude for different mass components. Future component-resolved anisotropy measurements by LHAASO will provide a crucial test of this scenario.

astro-ph.HE↗

arXiv2026

An emergence-oriented approach to circular formation

In this paper, we study the emergence of circular formation for agents in cyclic pursuit. Each agent is a unicycle traveling at a fixed common forward speed. We first establish a necessary and sufficient condition for the existence of circular formation in cyclic pursuit. Building on this theoretical foundation, we propose a control law that enables the spontaneous formation of circular formations through only local measurements. Notably, key geometric features -- the radius and agent spacing -- are not imposed externally but emerge naturally from the initial conditions of the group. This occurs because the closed-loop system possesses infinitely many non-isolated equilibria, each corresponding to a particular circular formation, and none are asymptotically stable. Consequently, analyzing individual equilibria is no longer informative, and attention is instead directed to the full invariant set (the set of all equilibria). Globally, it is disconnected. Locally, however, each equilibrium together with its neighboring equilibria forms a connected invariant set. This motivates a local stability analysis formulated at the level of invariant sets that are maximally connected. An accompanying stability criterion is then derived and applied to analyze small agent groups ($n \leq 3$), providing insights into the convergence mechanism. Finally, the proposed control law is extended to distance-dependent neighborhoods. Under this setting, the group converges into several clusters, most exhibiting a complete-graph topology. A preliminary stability analysis is then conducted for the case of a complete graph with $n=3$.

math.OC↗

arXiv2022

Prospective Study on Observations of γ-Ray Sources in the Galaxy Using the HADAR Experiment

The High Altitude Detection of Astronomical Radiation (HADAR) experiment is a refracting terrestrial telescope array based on the atmospheric Cherenkov imaging technique. It focuses the Cherenkov light emitted by extensive air showers through a large aperture water-lens system for observing very-high-energy-rays and cosmic rays. With the advantages of a large field-of-view (FOV) and low energy threshold, the HADAR experiment operates in a large-scale sky scanning mode to observe galactic sources. This study presents the prospects of using the HADAR experiment for the sky survey of TeV γ-ray sources from TeVCat and provids a one-year survey of statistical significance. Results from the simulation show that a total of 23 galactic point sources, including five supernova remnant sources and superbubbles, four pulsar wind nebula sources, and 14 unidentified sources, were detected in the HADAR FOV with a significance greater than 5 standard deviations (σ). The statistical significance for the Crab Nebula during one year of operation reached 346.0 σ and the one-year integral sensitivity of HADAR above 1TeV was ~1.3%-2.4% of the flux from the Crab Nebula.

astro-ph.HE↗