A $p$-adic Stark conjecture in the rank one setting

We give a new definition of a $p$-adic $L$-function for a mixed signature character of a real quadratic field and for a nontrivial ray class character of an imaginary quadratic field. We then state a $p$-adic Stark conjecture for this $p$-adic $L$-function. We prove our conjecture in the case when $p$ is split in the imaginary quadratic field by relating our construction to Katz’s $p$-adic $L$-function. We also provide numerical evidence for our conjecture in three examples.