ON j-INVARIANTS OF WEIERSTRASS EQUATIONS Horiuchi, Ryutaro;
A simple proof of the fact that the j-invariants for Weierstrass equations are invariant under birational transformations which keep the forms of Weierstrass equations is given by finding a non-trivial explicit birational transformation which sends a normalized Weierstrass equation to the same equation.
j-invariant;Weierstrass equation;elliptic curve;coverings;Riemann surface of genus one;
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