The Liouville quantum gravity boundary length as the variation process of the distance profile
For Brownian surfaces with boundary and an interior marked point, a natural observable to consider is the distance profile, defined as the process of distances from the marked point to a variable point lying on the boundary. When the boundary is parametrized by the natural length measure on it, this distance profile turns out to be locally absolutely continuous to Brownian motion, and as a result, the boundary length measure itself has a natural interpretation as the quadratic variation process of the distance profile. One can also consider $\gamma$-Liouville quantum gravity ($\gamma$-LQG), a one-parameter family of models of random geometry which is known to specialize to the case of Brownian geometry for the case $\gamma=\sqrt{8/3}$, and it is natural to wonder whether there is a natural analogue of the above result in this setting. In this talk, we first discuss $\gamma$-LQG and then look at a result providing such an analogue, namely, with $d_\gamma$ denoting the Hausdorff dimension of $\gamma$-LQG, the natural boundary length measure on a $\gamma$-LQG surface with boundary can be interpreted (up to a constant factor) as the $d_\gamma/2$-variation process of the distance profile from an interior point.