Iranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43620171130A descent method for explicit computations on curves198920161079ENK.FilomDepartment of Mathematical Sciences, Sharif University of Technology, Tehran, Iran.Journal Article20160713It is shown that the knowledge of a surjective morphism $Xto Y$ of complex curves can be effectively used to make explicit calculations. The method is demonstrated by the calculation of $j(ntau)$ (for some small $n$) in terms of $j(tau)$ for the elliptic curve with period lattice $(1,tau)$, the period matrix for the Jacobian of a family of genus-$2$ curves complementing the classic calculations of Bolza and explicit general formulae for branched covers of an elliptic curve with exactly one ramification point.http://bims.iranjournals.ir/article_1079_545c2bcc6cfdf11ec7739e314d3a881f.pdf