Resolution of the Cosmological Constant and Coincidence Problems in the Signed-Volume (SV0) Dark Energy Model

This manuscript is the tenth paper in a series establishing the Signed-Volume Effective-Fluid (SV0) model for dark energy. In Papers I-IX, we introduced the SV0 model, derived its microphysics, formulated its covariant structure, analyzed its perturbations, established its dynamical stability, forecasted its observational signatures, provided a string-theoretic embedding, and unified the early-universe bounce with late-time dark energy. In this tenth work, we demonstrate that the SV0 model naturally resolves the two most severe theoretical issues of the standard LambdaCDM paradigm: the cosmological constant problem and the coincidence problem. We show that the ~10^120 vacuum energy discrepancy is cancelled exactly by the symmetric two-sector geometric structure of SV0 (|V_A| + |V_B| = V0), leaving only the dynamical interaction energy A x(1-x) as the source of dark energy. Furthermore, we show that the SV0 tracker attractor drives the universe naturally towards x = 1/2, the point of maximum dark energy density, explaining the coincidence problem as a structural inevitability rather than an anthropic accident. Finally, we discuss how the modified expansion history of SV0 provides a natural mechanism to alleviate the Hubble tension. Related Works:Paper I: https://doi.org/10.5281/zenodo.24026844Paper II: https://doi.org/10.5281/zenodo.24032977Paper III: https://doi.org/10.5281/zenodo.24033838Paper IV: https://doi.org/10.5281/zenodo.24034927Paper V: https://doi.org/10.5281/zenodo.24035268Paper VI: https://doi.org/10.5281/zenodo.24035911Paper VII: https://doi.org/10.5281/zenodo.24038624Paper VIII: https://doi.org/10.5281/zenodo.24039486Paper IX: https://doi.org/10.5281/zenodo.24040648