Generalist vs Specialist Time Series Foundation Models: Investigating Potential Emergent Behaviors in Assessing Human Health Using PPG Signals. - Saurabh Kataria 001; Yi Wu; Zhaoliang Chen; Gloria Hyunjung Kwak; Yuhao Xu; Lovely Yeswanth Panchumarthi; Ran Xiao; Jiaying Lu 001; Ayca Ermis; Anni Zhao; Runze Yan; Alex Federov; et al. (CoRR, 2025)