We present observational constraints on the Bound Dark Energy Cold Dark Matter (BDE-CDM) model using DESI DR2 baryon acoustic oscillation measurements combined with Planck CMB data and Type Ia supernovae compilations (PantheonPlus, Union3, DESY5). In BDE-CDM, dark energy originates from the lightest meson field within a supersymmetric SU(3) dark gauge group with $N_f = 6$ flavors, governed by an inverse power-law potential $V(\phi) = \Lambda_{ c}^{ 4+2/3} \phi^{ -2/3}$. Unlike $\Lambda$CDM and $w_0w_a$CDM, the dark energy sector contains no free parameters -- the condensation scale $\Lambda_c$ and transition epoch $a_c$ are determined by gauge coupling unification constraints. The equation of state evolves from relativistic behavior ($w = 1/3$) before condensation through a kinetic-dominated stiff phase ($w \simeq 1$), approaching $w_0 = -0.9298 \pm 0.0003$ at present, with $w > -1$ maintained throughout cosmic history, avoiding phantom-regime instabilities. We obtain $\Lambda_{ c} = 43.93 \pm 0.13$~eV and $a_c = (2.489 \pm 0.007) \times 10^{ -6}$, consistent with theoretical predictions. The $w_0$-$w_a$ confidence contours are approximately 10,000 times smaller than those of $w_0w_a$CDM while achieving comparable fits, and remain stable across different supernova datasets. Statistical analysis yields $\Delta\mathrm{ DIC} = -6.77$ and $\Delta\mathrm{ AIC} = -8.97$ relative to $\Lambda$CDM for BAO+DESY5, constituting strong evidence favoring BDE-CDM model. The model predicts distinctive signatures including 25\% enhancement in the matter power spectrum at $k \approx 4.3\,h\,\mathrm{ Mpc}^{ -1}$. These results establish BDE-CDM as a theoretically motivated framework that successfully addresses the DESI-observed preference for dynamical dark energy while connecting particle physics with cosmological observations.
Categories: astro-ph.CO