Tags: #study-guides
Curves
Definitions
- What is an algebraic curve?
 - What is the genus of a curve?
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          Special types of varieties:
    
- What is a Fano variety?
 - What is a del Pezzo surface?
 - What is a ruled variety?
 - What is a uniruled variety?
 - What is an elliptic curve?
 - What is a hyperelliptic curve?
 - What is an abelian variety?
 - What is the Jacobian of a curve?
 - What is the Jacobian variety?
 - What is a Brill-Noether curve?
 - What is a Severi-Brauer variety?
 
 - What is the special divisor?
 - What is the ramification divisor?
 - What is the Frobenius map?
 - What is the j invariant?
 - What is an elliptic function?
 - What is the Hasse invariant?
 - What is the canonical embedding?
 - 
          What is the anticanonical embedding?
    
- The geometric genus?
 - The arithmetic genus?
 - The gonality?
 - The degree of a morphism \(C\to {\mathbb{P}}^r\)?
 
 - What is the dual curve?
 - What is the resultant?
 - What is the Kodaira dimension?
 - What is the Todd genus?
 - What is a minimal model of a smooth projective variety?
 - What is an elliptic fibration?
 - 
          Types of surfaces:
    
- An Enriques surface?
 - A K3 surface?
 - An elliptic surface?
 - A hyperelliptic surface?
 - An abelian surface?
 - 
          What is the Hirzebruch surface?
    
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          Examples: 
         
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          Examples: 
 
 - What is a log resolution?
 - What is a rational curve?
 - What is a stable map?
 - What is a reducible curve?
 - What is devissage?
 - What is a crepant map?
 - What is a complete intersection?
 - What are ADE singularities?
 - What is the Fermat quartic?
 
Results
- What is Castelnuovo’s theorem?
 - What is the Riemann-Roch theorem for curves?
 - 
          What is the Riemann-Hurwitz theorem for curves?
    
- \(2-2 g_{1}=2\left(2-2 g_{0}\right)-\displaystyle\sum_{s \in X^{\mathrm{ram}}}\left(e_{s}-1\right)\)
 
 - What is Hurwitz’s theorem?
 - What is the classification of curves in \({\mathbb{P}}^3\)?
 - What is the Riemann-Hurwitz formula?
 - What is the genus formula for plane curves?
 - What is the Brill-Noether theorem?
 - Why is every genus 2 curve hyperellptic? Why is this not even generically true for \(g\geq 3\)?
 - How can you view a curve as a ramified cover of ${\mathbb{P}}^1_{/ {k}} $?
 - What is the cohomological criterion for ampleness?
 - Why is Zariski’s theorem true?
 - What is the Hodge index theorem?
 - What is Mori’s theorem?
 - What is Zariski’s main theorem?
 - What is the minimal model program for surfaces?
 
Problems
- Show that if \(C\) is a smooth proper curve of genus \(g(C)\geq 2\), then \({\sharp}\mathop{\mathrm{Aut}}(G) < \infty\).
 - Show that given \(\pi: X \rightarrow Y\), \(Y\) is integrally closed in \(K(X)\) over \(K(Y)\) if and only if \({\mathcal{O}}_{Y} \rightarrow \pi_{*} {\mathcal{O}}_{X}\) is an isomorphism (i.e., \(\pi\) is \({\mathcal{O}}\)-connected).
 - Use Tsen’s theorem to show that given a flat family \(X\to Y\) with \(Y\) a curve where the fibers smooth curves of genus 0, this determines a Zariski \({\mathbb{P}}^1{\hbox{-}}\)bundle iff there exists a relative degree 1 line bundle on \(X\) over \(Y\).