# ⚛  L1 Principle — Dark Matter — Galactic Rotation & Halo Profile

**ID:** `L1-912` · **Status:** ⊙ Testnet (genesis catalog)

> **🌐 Domain:** Astrophysics — *Dark Matter Halos*

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## 🧠 1. Introduction

**Dark Matter — Galactic Rotation & Halo Profile** is a **inverse problem**, within the **Dark Matter Halos** sub-domain of **Astrophysics**.

## ⚙ 2. Forward Model

```
Circular velocity v(r)=√(G·M(r)/r) with an NFW halo ρ(r)=ρ_s/[(r/r_s)(1+r/r_s)²]; infer halo parameters from rotation curves.
```

## 🔬 3. Physics Fingerprint

| Property | Value |
|---|---|
| Domain | Astrophysics |
| Sub domain | Dark Matter Halos |

## 📡 4. Measurement Model

| Metric | Value |
|---|---|
| Metric | rotcurve_chi2 |

## ⚖ 6. Hardness Function

Hardness scales as **`grand_challenge`** on **rotcurve_chi2**.

## 💾 7. Reference Dataset

- **SPARC galaxy rotation-curve database** · weight 0.6 · IPFS _(not pinned yet)_
- **THINGS HI velocity fields** · weight 0.4 · IPFS _(not pinned yet)_

**Staked PWM:** 5000.0

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## File Mapping

This bundle consists of: `L1-912.md`, `L1-912.json`.

| File | Role | How to regenerate |
|------|------|-------------------|
| `L1-912.md` | Source of truth — edit this | Human or LLM |
| `L1-912.json` | Structured metadata for the registry | LLM regenerates from the sections above |

**Prompt for your LLM after editing this Markdown:**

> Read the attached Markdown. Regenerate the sibling `.json` so every field matches.
> Preserve the schema documented in the rows above.
> Output each file in its own fenced code block tagged with the filename.
> Output only the JSON object.

_This Markdown was auto-synthesized from the catalog row for `L1-912`._
_Edit it, regenerate the JSON, and submit at [/submit](/submit) to claim the artifact._