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Triviality, ampleness, nefness, and bigness of the tangent bundle

Let $X$ be a smooth projective connected variety over $\mathbb{C}$ and let $T_X$ be its tangent bundle. If $T_X$ is ample, then $X$ is isomorphic to a projective space by Mori's theorem. If $T_X$ is ...
Pat's user avatar
  • 513
2 votes
0 answers
157 views

Is the cotangent sheaf of the symmetric product reflexive?

Let $X$ be a smooth projective surface and $X^{(n)}:= X^n/\mathfrak{S}_n$ be the nth symmetric product of $X$. When is the cotangent sheaf of $X^{(n)}$ reflexive?
Sourav's user avatar
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1 vote
0 answers
159 views

Affinization map of cotangent bundle is proper/projective?

Given a cotangent bundle of a projective variety $Y=T^*X,$ do we know that its affinization map, $$Y \rightarrow \mathrm{Spec}(H^0(Y,\mathscr{O}_Y))$$ is proper or projective?
Filip's user avatar
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1 vote
0 answers
309 views

Restriction of the sheaf of relative differentials

Let $f:X\rightarrow C$ be a morphism, where $C$ is a smooth curve, and let $\Omega_f$ be the sheaf of relative differentials. For $t\in C$ let $i_t:X_t = f^{-1}(t)\rightarrow X$ be the inclusion of ...
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A question about the sheaf supported on the zero section

Let $X$ be the total space of the cotangent sheaf on $\mathbb{P}^{2}$ and $i \colon \mathbb{P}^{2} \hookrightarrow X$ be thezero section. Suppose that $E$ is a coherent sheaf on $X$ which is set-...
Tianle Mao's user avatar
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0 answers
161 views

Projectivization of the normal bundle of $\mathbb P^4$ in the 10-spinor variety

Let $X=S_{10} \subset \mathbb P^{15}$ be the 10-dimensional spinor variety in its minimal embedding. Consider a $\mathbb P^4 \subset S_{10}$, hence we can define the normal bundle $N=N_{\mathbb P^4|S_{...
Bobech's user avatar
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