内容简介
ThisVolumegivesanaccountoftheprincipalmethodsusedindevelopingatheoryofalgebraicvarietiesinspaceofndimensions.Applicationsofthesemethodsarealsogiventosomeofthemoreimportantvarietieswhichoccurinprojectivegeometry.Itwasorigina113ourintentiontoincludeanaccountofthearithmetictheoryofvarieties,andofthefoundationsofbirationalgeometry,butithasturnedouttobemoreconvenienttoreservethesetopicsforathirdvolume.Thetheoryofalgebraicvarietiesdevelopedinthisvolumeisthereforemainlyatheoryofvarietiesinprojectivespace.Inwritingthisvolumewehavebeenfacedwithtwoproblems:thedifficultquestionofwhatmustgoinandwhatshouldbeleftout,andtheproblemofthedegreeofgeneralitytobeaimedat.Asourobjectivehasbeentogiveanaccountofthemodernalgebraicmethodsavailabletogeometers,wehavenotsoughtgeneralityforitsownsake.Thereisstillenoughtobedoneintherealmofclassicalgeometrytogivethesemethodsallthescopethatcouldbedesired,andhaditbeenpossibletoconfineourselvestotheclassicalcaseofgeometryoverthefieldofcomplexnumbers,weshouldhavebeencontenttodoso.Butinordertoputtheclassicalmethodsonasoundbasis,usingalgebraicmethods,itisnecessarytoconsidergeometryovermoregeneralfieldsthanthefieldofcomplexnumbers.However,iftheultimateobjectistoprovideasoundalgebraicbasisforclassicalgeometry,itisonlynecessarytoconsiderfieldswithoutcharacteristic.Sincegeometryoveranyfieldwithoutcharacteristicconformstothegeneralpatternofgeometryoverthefieldofcomplexnumbers,wehavedevelopedthetheoryofalgebraicvarietiesoveranyfieldwithoutcharacteristic.Thusfieldswithfinitecharacteristicarenotusedinthisbook.