across decades in radius. This opens up another form of feedback: in feeding the planet, the disc can have its entire surface density profile changed (e.g., @ld_2006; @znh_2011; @o_2016).

Our work is organized as follows. In section \[sec:consumption\] we describe how Lindblad repulsion and planetary accretion of disc gas (“consumption”) work together to determine gap depths and surface density profiles of viscous circumstellar accretion discs. Our largely analytic considerations are supplemented with simple numerical experiments modeling planet-disc interactions and disc evolution in 1D (orbital radius). In section \[sec:consumption\] we fix, for simplicity, the planet mass; in section \[sec:mass\], we allow the planet mass to grow freely and solve the full two-way feedback problem. In section \[sec:windy\], motivated by recent theoretical and observational developments, we consider discs that transport their mass not by viscous diffusion but rather by angular momentum losses from magnetized winds. For such inviscid, wind-driven discs, accretion is not diffusive but purely advective, and embedded planets carve out especially deep gaps in the absence of viscous backflow. We summarize and discuss the implications of our findings on gas giant masses and disc structure, including the structure of transitional discs, in section \[sec:sum\].

A simplified study such as ours 