This report synthesises findings from 2 peer-reviewed papers addressing the following research question: How do hyperbolic and Euclidean contrastive learning models scale with increasing model size and training data size in zero-shot cross-lingual retrieval for XOR-TyDi QA, measured by recall@k and NDCG. 5 claims were extracted from source literature; 5 were independently verified against retrieved documents. An automated multi-reviewer quality assessment produced a score of 8.0/10. This report is a machine-generated literature synthesis and does not constitute original research.Research goal: How do hyperbolic and Euclidean contrastive learning models scale with increasing model size and training data size in zero-shot cross-lingual retrieval for XOR-TyDi QA, measured by recall@k and NDCG?Autonomous literature synthesis. Automated review score: 8.0/10. Full text and citation available at Assignee Research.