Bayesian posterior odds across three hypotheses: single IMBH, dark stellar cluster, or no central mass. Adjust the weight of each evidence line and watch the verdict update in real time.
These bounds are irreconcilable if a single IMBH explanation is assumed. This tool treats that tension as a first-class input. The dark-cluster hypothesis exists precisely to dissolve it.
Each evidence line contributes two Bayes factors. The first compares IMBH vs dark cluster — how much does this evidence distinguish between a single massive object and a diffuse cluster? The second compares any central mass vs nothing.
Sliders are in log₁₀ units. A value of +1 means the evidence is 10× more likely given IMBH than given the alternative. Neutral (0) means the evidence doesn't discriminate.
Three hypotheses: HIMBH (single intermediate-mass black hole), HDC (dark stellar cluster of stellar-mass remnants), HNULL (no significant central mass concentration).
For each evidence line i, two log₁₀ Bayes factors are entered: r_i = log₁₀(L_IMBH / L_DC) and s_i = log₁₀(L_DC / L_NULL). Unnormalized posterior weights: w_IMBH ∝ prior_IMBH × 10^Σ(r_i + s_i), w_DC ∝ prior_DC × 10^Σs_i, w_NULL ∝ prior_NULL. Normalize to 100%.
Default Bayes factors reflect conservative interpretations of published literature as of June 2026. They are starting points — adjust them to represent your own reading of each paper.
Häberle et al. 2024 measure a stellar kinematic lower bound of ≥ 8,200 M☉. Bañares-Hernández et al. 2025 derive a pulsar-timing upper bound of ≤ 6,000 M☉. These bounds assume a single point mass; a dark cluster of stellar-mass black holes is one framework that could dissolve the tension. This tool makes that choice explicit through the prior and the dark-cluster Bayes factors.