文摘
The universal cover or the covering group of a hyperbolic Riemann surface \(X\) is important but hard to express explicitly. It can be, however, detected by the uniformization and a suitable description of \(X\) . Beardon proposed five different ways to describe twice-punctured disks using fundamental domain, hyperbolic length, collar and extremal length in 2012. We parameterize a once-punctured annulus \(A\) in terms of five parameter pairs and give explicit formulas about the hyperbolic structure and the complex structure of \(A\) . Several degenerate cases are also treated.