Amoebas, their dimensions, and torus actions

Abstract: the amoeba of an algebraic variety X in (C^*)^n is its image
in R^n under the log-absolute value map. After discussing some
well-known basic results, I present our answer to a question by
Nisse-Sottile on the dimension of an amoeba. The expected (real)
dimension is 2 times the complex dimension of X, and we show that a drop
in dimension is always caused by a near torus action. (Joint work with
Johannes Rau and Chi Ho Yuen.)