Some interesting birational morphisms of smooth affine quadric 3-folds <sup>*</sup>
Some interesting birational morphisms of smooth affine quadric 3-folds <sup>*</sup>
Abstract We study a family of birational maps of smooth affine quadric 3-folds, over the complex numbers, of the form <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mi>x</mml:mi> <mml:mn>1</mml:mn> </mml:msub> <mml:msub> <mml:mi>x</mml:mi> <mml:mn>4</mml:mn> </mml:msub> <mml:mo>−</mml:mo> <mml:msub> <mml:mi>x</mml:mi> <mml:mn>2</mml:mn> </mml:msub> <mml:msub> <mml:mi>x</mml:mi> <mml:mn>3</mml:mn> </mml:msub> <mml:mo>=</mml:mo> </mml:mrow> </mml:math> constant, which seems to have some …