We study the consistency between high-pT nuclear suppression (R_AA) and
elliptic flow (v2) using Gyulassy-Levai-Vitev (GLV) energy loss or a simpler
power-law dE/dL formula, for a variety of bulk evolution models. The results
generally confirm our earlier work [arXiv:1305.1046] that found suppressed
elliptic flow for transversely expanding media. One exception is the set of
hydrodynamic solutions used recently [arXiv:1305.6458] by Betz and Gyulassy,
which give significantly higher v2 but unfortunately assume unrealistic
bag-model equation of state. On the other hand, we show that covariant
treatment of energy loss introduces an interplay between jet direction and
hydrodynamic flow of the medium, which largely counteracts elliptic flow
suppression caused by transverse expansion.Comment: Presentation at Hard Probes 2013 (4 pages, 8 PDF plots, Elsevier
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