The Similarity of Abundance Ratio Trends and Nucleosynthetic Patterns in
  the Milky Way Disk and Bulge
  We compare abundance ratio trends in a sample of $\sim 11,000$ Milky Way
bulge stars ($R_{\rm GC} < 3$ kpc) from the Apache Point Observatory Galactic
Evolution Experiment (APOGEE) to those of APOGEE stars in the Galactic disk
($5$ kpc $< R_{\rm GC} < 11$ kpc). We divide each sample into low-Ia
(high-[Mg/Fe]) and high-Ia (low-[Mg/Fe]) populations, and in each population we
examine the median trends of [X/Mg] vs. [Mg/H] for elements X = Fe, O, Na, Al,
Si, P, S, K, Ca, V, Cr, Mn, Co, Ni, Cu, and Ce. To remove small systematic
trends of APOGEE abundances with stellar $\log(g)$, we resample the disk stars
to match the $\log(g)$ distributions of the bulge data. After doing so, we find
nearly identical median trends for low-Ia disk and bulge stars for all
elements. High-Ia trends are similar for most elements, with noticeable
(0.05-0.1 dex) differences for Mn, Na, and Co. The close agreement of abundance
trends (with typical differences $\lesssim 0.03$ dex) implies that similar
nucleosynthetic processes enriched bulge and disk stars despite the different
star formation histories and physical conditions of these regions. For example,
we infer that differences in the high mass slope of the stellar initial mass
function (IMF) between disk and bulge must have been $\lesssim 0.30$. This
agreement, and the generally small scatter about the median sequences, means
that one can predict all of a bulge star's APOGEE abundances with good accuracy
knowing only its measured [Mg/Fe] and [Mg/H] and the observed trends of disk
stars.
