Show HN: Analog Hawking radiation modeling in laser–plasma flows

A computational framework for modeling analog Hawking radiation in laser-plasma systems. Simulates sonic horizons in flowing plasmas and calculates quantum field theory spectra with novel hybrid fluid-plasma mirror coupling.

In flowing fluids, sound waves can become trapped when the local flow velocity v exceeds the sound speed c_s. This creates a sonic horizon - an acoustic analog to a black hole's event horizon where information cannot escape upstream.

The key physics parameter is the surface gravity:

Just as black holes emit Hawking radiation due to quantum vacuum fluctuations near the event horizon, these analog systems can produce thermal radiation with temperature:

⚠️ Note: This is a speculative, non-physical model for computational exploration

The framework explores a novel scenario where high-intensity laser pulses create localized plasma mirrors within an existing fluid flow, building on the AnaBHEL (Analog Black Hole Evaporation via Lasers) framework developed by Chen, Mourou, and collaborators:

1. Background Fluid: A flowing medium (gas jet, liquid stream, or pre-existing plasma) with sonic horizon formation
2. Laser Ionization: Ultra-intense laser pulses (>10¹⁸ W/m²) instantly ionize matter, creating dense electron clouds
3. Plasma Mirror Formation: Free electrons oscillate in the laser field, creating a reflective "mirror" that can be accelerated
4. Hybrid Coupling: The accelerating plasma mirror locally enhances the fluid's surface gravity

Speculative Physics Model:

Where the laser essentially "paints" accelerating plasma mirrors onto the existing fluid background to enhance Hawking radiation signatures.

AnaBHEL Foundation: This approach extends the plasma mirror concepts from Chen & Mourou (2015) and the AnaBHEL collaboration (Chen et al., 2022), but the hybrid fluid-mirror coupling represents a speculative extension beyond established theory.

Important: This coupling mechanism lacks established theoretical foundation and should be considered a computational thought experiment rather than a physics prediction.

1. Horizon Detection: Identifies sonic horizon formation regions in plasma flow profiles
2. Quantum Spectra: Calculates Hawking radiation using near-horizon WKB graybody factors
3. Speculative Hybrid Coupling: Explores laser-painted plasma mirror enhancement of fluid horizons
4. Radio Detection: Estimates detectability with realistic antenna parameters

The framework's primary contribution is systematic exploration of speculative hybrid coupling between fluid sonic horizons and laser-created plasma mirrors:

The Concept:

• Fluid Background: Flowing medium with natural sonic horizon formation
• Laser Intervention: Ultra-intense pulses create localized plasma mirrors via ionization
• Hybrid Enhancement: Accelerating mirrors locally boost the effective surface gravity

Mathematical Model:

⚠️ Speculative Nature: This approach represents a computational thought experiment exploring whether laser-painted plasma mirrors could enhance analog Hawking signatures. The coupling mechanism lacks established theoretical foundation.

• Python ≥ 3.8 with NumPy ≥ 1.21, SciPy, Matplotlib
• Runtime: Minutes on laptop for demos, hours for full parameter sweeps
• Validation: 26/26 unit and integration tests passing

Key results in results/full_pipeline_summary.json:

• kappa: Surface gravity values (s⁻¹)
• T_hawking_K: Hawking temperature (K)
• T_sig_K: Antenna signal temperature (K)
• t5sigma_s: 5σ detection time (s) for T_sys=30K, B=100MHz
• hybrid_used: Boolean flag for hybrid mode

This framework implements a conservative, physics-based approach to analog Hawking radiation:

1. Horizon Detection: Systematic identification of sonic horizon regions where ∇(v² - c_s²) changes sign
2. Quantum Calculation: Near-horizon WKB approximation for graybody transmission factors
3. Hybrid Enhancement: Phenomenological plasma mirror coupling via AnaBHEL mapping
4. Detection Modeling: Radiometer-style SNR with configurable system parameters

• Identical Normalization: All comparisons use same emitting area (1×10⁻⁶ m²), solid angle (0.05 sr), coupling efficiency (0.1)
• Conservative Parameters: AnaBHEL model κ_mirror = 2πη_a/D rather than optimistic scaling
• Comprehensive Testing: 26 unit and integration tests covering all physics modules

• Spatial Scale: Envelope/skin-depth modeling (no full PIC validation in this repository)
• Transmission: WKB graybody factors near horizons, conservative fallbacks elsewhere
• Detection: Radiometer-style SNR with user-configurable T_sys and bandwidth
• Hybrid Mapping: Phenomenological mirror→κ relation for comparative analysis

This is a computational modeling framework for exploring speculative physics scenarios:

• Speculative coupling: The hybrid fluid-mirror interaction lacks established theoretical foundation
• Phenomenological mapping: Plasma mirror → surface gravity relation is empirical (AnaBHEL model)
• No experimental validation: Pure computational exploration of "what if" scenarios
• Order-of-magnitude estimates: Results indicate trends, not precise predictions
• Hardware considerations: Real implementation would face numerous practical challenges

Intended use: Computational thought experiment to explore whether laser-enhanced analog systems could theoretically boost Hawking radiation signatures. Not a prediction of experimental feasibility.

• docs/Overview.md: Physics background and methodology
• docs/Methods.md: Detailed computational approaches
• docs/Results.md: Example outputs and interpretation
• docs/Limitations.md: Comprehensive scope discussion
• TESTING_PLAN.md: Validation methodology and test coverage

If you use this computational framework in your research, please cite both this work and the foundational AnaBHEL research it builds upon:

This Framework:

Foundational AnaBHEL Work:

1. Enhanced Validation: Complete systematic testing outlined in TESTING_PLAN.md
2. PIC Integration: Full WarpX integration beyond current mock mode
3. Extended Studies: Comprehensive parameter sweeps and cross-validation
4. Hardware Modeling: Realistic observatory geometry and noise pipelines

Key literature foundations:

• Foundational Theory: Unruh (1981) - original analog Hawking radiation proposal; Hawking (1974, 1975) - black hole radiation
• AnaBHEL Framework: Chen & Mourou (2015) - accelerating plasma mirrors; Chen et al. (2022) - AnaBHEL experimental concept
• Experimental Analog Gravity: Steinhauer (2016) - first strong evidence; Faccio & Wright (2013) - laser-fluid bridges
• Ultra-Intense Lasers: Mourou et al. (2006) - Nobel laureate work enabling AnaBHEL technology

Key Research Groups:

• LeCosPA (National Taiwan University) - AnaBHEL theory development (P. Chen)
• IZEST (École Polytechnique) - Ultra-high intensity lasers (G. Mourou)
• Xtreme Light Group (University of Glasgow) - Laser-based analog gravity (D. Faccio)
• Technion - Experimental analog Hawking radiation (J. Steinhauer)

Complete bibliography available in docs/REFERENCES.md.

Framework Version: 0.1.0 | License: MIT | Tests: 26/26 passing | Updated: October 2025