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Hao-Yang Yen

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Research Interests

My research spans statistical physics, celestial mechanics, and dynamical systems. I study the statistical properties of complex and stochastic dynamical systems (e.g., epidemic and ecological models), and N-body problems in celestial mechanics—stability of planetary systems, symmetry breaking, and phase-transition-like phenomena. I’m also interested in connections between statistical physics and computer/data science.

  • Stochastic dynamics: spectra, mixing, universality, rare events
  • Celestial mechanics: N-body stability, central configurations, symmetry
  • Bridges: statistical physics × algorithms / data science

Publications

Selected papers and preprints. Full list upon request.

  1. H.-Y. Yen, et al. Breakdown of Directed Percolation Universality under Boundary Effects in Non-Reciprocal Absorbing-State Transitions Manuscript under preparation, 2025
  2. H.-Y. Yen, et al. Non-Hermitian Ecology of Turbulence: Loop Spectra, Skin Effect, and the Boundary Shift of Transition Manuscript under preparation, 2025

Current Research Areas

Stochastic Dynamics

Tensor Networks for Classical Stochastic Systems

We investigate why tensor networks—originally for quantum many-body systems—can model classical stochastic dynamics. By clarifying the underlying principles beyond 1D cases, we connect quantum and classical formalisms through operator/spectral viewpoints.

  • Tensor networks
  • Rare events
  • Stochastic processes
  • Many-body
Spectral Theory

Spectra, Phase Transitions & Universality

Stochastic generators expose deep links between spectra and macroscopic behaviors. I study how eigenvalue distributions relate to universality classes in nonequilibrium systems. Currently, I found spectral topology can affect dynamics and phase transitions in turbulence.

  • Generators
  • Turbulence
  • Spectral gap
  • Spectral topology
  • Phase transition and universality
Celestial Mechanics

Central Configurations & Symmetry Breaking

Central configurations yield self-similar N-body motions (homothetic expansion/contraction or rigid rotation). I explore analogies to symmetry breaking in statistical physics and map phase-diagram-like structures for symmetric 5-body configurations.

  • Hamiltonian dynamical systems
  • N-body
  • Symmetry
  • Bifurcation
  • Computer Algebra