Toward a Black Hole Origin for the Cosmological Dipole Angular Momentum Inheritance from a Parent Black Hole

The cosmological principle—the assumption of large-scale statistical isotropy andhomogeneity—is a foundational postulate of the standard ΛCDM model. Whileextensively supported by CMB and large-scale structure observations, its status asan observational fact rather than a contingent initial condition is properly subjectto empirical test. Several observational anomalies, including dipolar asymmetries inradio galaxy counts and reports of parity violation in galaxy spin directions, havebeen noted in the literature, though their interpretation remains a subject of activedebate. Set apart from the question of whether these specific signals are cosmological or systematic, this paper develops a theoretical framework that explores thecosmological consequences of a concrete initial condition scenario: the hypothesisthat our universe emerged from a rotating black hole in a parent spacetime. We workwithin a unified theoretical framework combining Einstein-Cartan gravity—whichprovides the torsional spin-spin repulsion that can trigger a non-singular bounce atPlanckian densities—with the running vacuum model (RVM), in which the effectivecosmological term evolves dynamically as Λ(H) = αH2 + βH4/M2Pl and drives thepost-bounce expansion. The bounce replaces the classical singularity with a new,causally disconnected FLRW universe—a “child universe.” The parent black hole’sangular momentum, a conserved global charge defined and measured in the parentspacetime, is transferred not through a horizon-crossing signal, but as a boundary1condition at the bounce hypersurface: the same axial symmetry that characterizedthe parent Kerr geometry imprints itself as a preferred direction in the initial conditions of the child FLRW patch. We compute the resulting primordial angular momentum spectrum and its late-time observational signatures, including CMB vectormode B-polarization, a specific dark-energy equation-of-state trajectory w(z), and aparity asymmetry in galaxy spin directions. The inherited angular momentum canbe understood as a birthmark of our universe—an imprint of the parent blackhole’s rotation encoded at the bounce, and the only surviving observable trace ofour cosmic origins. The model makes quantitative, falsifiable predictions for Euclid,LSST, LiteBIRD, and CMB-S4, with explicit exclusion thresholds. The frameworkis constructed to be compatible with general relativity on all tested scales and withinthe ΛCDM expansion history; the angular momentum seed constitutes the sole newparameter.