The New Dark Matter Density Profile from JWST JADES Galaxies

We present the first dark matter density profile derived directly from James Webb Space Telescope JADES Data Release~3 NIRSpec observations of $N=587$ galaxies spanning the cosmic noon epoch $1.5\le z\le 3.5$. From each NIRSpec G235M/G395M spectrum we extract the H$\alpha$ emission-line velocity dispersion ${\sigma }_{\mathrm{h}\mathrm{a}}$, stack galaxies in four redshift bins of $\mathrm{\Delta }z=0.5$, and reconstruct representative group rotation curves within the General Theory of Relativity. Fitting the four-parameter modified exponential model and deriving the exact GTR energy density, we reduce the profile to a compact $[2\mathrm{/}3]$ Padé approximant with all coefficients determined in closed form from JWST observations. The profile is cusp-free, fully analytic, and redshift-dependent. Energy conditions, causality, and orbital stability are all satisfied. Most strikingly, the central density $\rho (0)$ varies by less than $15\mathrm{\%}$ across $z=1.5$–$3.5$ despite a $35\mathrm{\%}$ decline in the asymptotic rotation velocity, revealing a universal dark matter core saturation density at cosmic noon decoupled from baryonic evolution.