text: 458,15,879318419325190144,1545756036,Mike Boylan-Kolchin,"New paper from V. Robles on cores in dwarf galaxies: sensitive to feedback in CDM, robust to feedback in SIDM. <LINK> <LINK> Although, <LINK> (also out today) argues cores may be observational artifacts. Can't imagine that will be controversial.... @caprastro I like it! Having a few more comparable systems would be reassuring. Hard for me to believe that cores are all erroneous measurements. You? @caprastro Good to know, thanks. Do they have reasonably precise age estimates (say, w/i 2 Gyr)? Formation time seems to be important for core argument",https://arxiv.org/abs/1706.07514v1,"We compare a suite of four simulated dwarf galaxies formed in 10$^{10} M_{\odot}$ haloes of collisionless Cold Dark Matter (CDM) with galaxies simulated in the same haloes with an identical galaxy formation model but a non-zero cross-section for dark matter self-interactions. These cosmological zoom-in simulations are part of the Feedback In Realistic Environments (FIRE) project and utilize the FIRE-2 model for hydrodynamics and galaxy formation physics. We find the stellar masses of the galaxies formed in Self-Interacting Dark Matter (SIDM) with $\sigma/m= 1\, cm^2/g$ are very similar to those in CDM (spanning $M_{\star} \approx 10^{5.7 - 7.0} M_{\odot}$) and all runs lie on a similar stellar mass -- size relation. The logarithmic dark matter density slope ($\alpha=d\log \rho / d\log r$) in the central $250-500$ pc remains steeper than $\alpha= -0.8$ for the CDM-Hydro simulations with stellar mass $M_{\star} \sim 10^{6.6} M_{\odot}$ and core-like in the most massive galaxy. In contrast, every SIDM hydrodynamic simulation yields a flatter profile, with $\alpha >-0.4$. Moreover, the central density profiles predicted in SIDM runs without baryons are similar to the SIDM runs that include FIRE-2 baryonic physics. Thus, SIDM appears to be much more robust to the inclusion of (potentially uncertain) baryonic physics than CDM on this mass scale, suggesting SIDM will be easier to falsify than CDM using low-mass galaxies. Our FIRE simulations predict that galaxies less massive than $M_{\star} < 3 \times 10^6 M_{\odot}$ provide potentially ideal targets for discriminating models, with SIDM producing substantial cores in such tiny galaxies and CDM producing cusps. ","] SIDM on FIRE: Hydrodynamical Self-Interacting Dark Matter simulations of