Too Polite to Disagree: Understanding Sycophancy Propagation in Multi-Agent Systems. - Vira Kasprova; Amruta Parulekar; Abdulrahman AlRabah; Krishna Agaram; Ritwik Garg; Sagar Jha; Nimet Beyza Bozdag; Dilek Hakkani-Tur (CoRR, 2026)