\begin{equation} \DeclareMathOperator\Gr{Gr} \DeclareMathOperator\LGr{LGr} \DeclareMathOperator\OGr{OGr} \DeclareMathOperator\SGr{SGr} \DeclareMathOperator\Kzero{K_0} \DeclareMathOperator\index{i} \DeclareMathOperator\rk{rk} \end{equation}

Grassmannian.info

A periodic table of (generalised) Grassmannians.

Generalised Grassmannian of type E7/P2

Betti numbers
\begin{align*} \mathrm{b}_{ 0 } &= 1 \\ \mathrm{b}_{ 2 } &= 1 \\ \mathrm{b}_{ 4 } &= 1 \\ \mathrm{b}_{ 6 } &= 2 \\ \mathrm{b}_{ 8 } &= 3 \\ \mathrm{b}_{ 10 } &= 4 \\ \mathrm{b}_{ 12 } &= 5 \\ \mathrm{b}_{ 14 } &= 7 \\ \mathrm{b}_{ 16 } &= 8 \\ \mathrm{b}_{ 18 } &= 10 \\ \mathrm{b}_{ 20 } &= 12 \\ \mathrm{b}_{ 22 } &= 14 \\ \mathrm{b}_{ 24 } &= 16 \\ \mathrm{b}_{ 26 } &= 18 \\ \mathrm{b}_{ 28 } &= 20 \\ \mathrm{b}_{ 30 } &= 22 \\ \mathrm{b}_{ 32 } &= 24 \\ \mathrm{b}_{ 34 } &= 25 \\ \mathrm{b}_{ 36 } &= 26 \\ \mathrm{b}_{ 38 } &= 27 \\ \mathrm{b}_{ 40 } &= 28 \\ \mathrm{b}_{ 42 } &= 28 \\ \mathrm{b}_{ 44 } &= 28 \\ \mathrm{b}_{ 46 } &= 27 \\ \mathrm{b}_{ 48 } &= 26 \\ \mathrm{b}_{ 50 } &= 25 \\ \mathrm{b}_{ 52 } &= 24 \\ \mathrm{b}_{ 54 } &= 22 \\ \mathrm{b}_{ 56 } &= 20 \\ \mathrm{b}_{ 58 } &= 18 \\ \mathrm{b}_{ 60 } &= 16 \\ \mathrm{b}_{ 62 } &= 14 \\ \mathrm{b}_{ 64 } &= 12 \\ \mathrm{b}_{ 66 } &= 10 \\ \mathrm{b}_{ 68 } &= 8 \\ \mathrm{b}_{ 70 } &= 7 \\ \mathrm{b}_{ 72 } &= 5 \\ \mathrm{b}_{ 74 } &= 4 \\ \mathrm{b}_{ 76 } &= 3 \\ \mathrm{b}_{ 78 } &= 2 \\ \mathrm{b}_{ 80 } &= 1 \\ \mathrm{b}_{ 82 } &= 1 \\ \mathrm{b}_{ 84 } &= 1 \end{align*}
Basic information
dimension
42
index
14
Euler characteristic
576
Betti numbers
$\mathrm{b}_{ 0 } = 1$, $\mathrm{b}_{ 2 } = 1$, $\mathrm{b}_{ 4 } = 1$, $\mathrm{b}_{ 6 } = 2$, $\mathrm{b}_{ 8 } = 3$, $\mathrm{b}_{ 10 } = 4$, $\mathrm{b}_{ 12 } = 5$, $\mathrm{b}_{ 14 } = 7$, $\mathrm{b}_{ 16 } = 8$, $\mathrm{b}_{ 18 } = 10$, $\mathrm{b}_{ 20 } = 12$, $\mathrm{b}_{ 22 } = 14$, $\mathrm{b}_{ 24 } = 16$, $\mathrm{b}_{ 26 } = 18$, $\mathrm{b}_{ 28 } = 20$, $\mathrm{b}_{ 30 } = 22$, $\mathrm{b}_{ 32 } = 24$, $\mathrm{b}_{ 34 } = 25$, $\mathrm{b}_{ 36 } = 26$, $\mathrm{b}_{ 38 } = 27$, $\mathrm{b}_{ 40 } = 28$, $\mathrm{b}_{ 42 } = 28$, $\mathrm{b}_{ 44 } = 28$, $\mathrm{b}_{ 46 } = 27$, $\mathrm{b}_{ 48 } = 26$, $\mathrm{b}_{ 50 } = 25$, $\mathrm{b}_{ 52 } = 24$, $\mathrm{b}_{ 54 } = 22$, $\mathrm{b}_{ 56 } = 20$, $\mathrm{b}_{ 58 } = 18$, $\mathrm{b}_{ 60 } = 16$, $\mathrm{b}_{ 62 } = 14$, $\mathrm{b}_{ 64 } = 12$, $\mathrm{b}_{ 66 } = 10$, $\mathrm{b}_{ 68 } = 8$, $\mathrm{b}_{ 70 } = 7$, $\mathrm{b}_{ 72 } = 5$, $\mathrm{b}_{ 74 } = 4$, $\mathrm{b}_{ 76 } = 3$, $\mathrm{b}_{ 78 } = 2$, $\mathrm{b}_{ 80 } = 1$, $\mathrm{b}_{ 82 } = 1$, $\mathrm{b}_{ 84 } = 1$
$\mathrm{Aut}^0(\mathrm{E}_{7}/\mathrm{P}_{2})$
adjoint group of type $\mathrm{E}_{ 7 }$
$\pi_0\mathrm{Aut}(\mathrm{E}_{7}/\mathrm{P}_{2})$
$1$
$\dim\mathrm{Aut}^0(\mathrm{E}_{7}/\mathrm{P}_{2})$
133
Projective geometry
minimal embedding

$\mathrm{E}_{7}/\mathrm{P}_{2}\hookrightarrow\mathbb{P}^{ 911 }$

degree
230629602357872640
Hilbert series
1, 912, 253935, 32995248, 2457458575, 118861039440, 4061118864660, 104114789500800, 2095350182853408, 34279106505180160, 468620731551643872, 5474059247498898816, 55645606128266708700, 499788275805501361360, 4017247956270188974125, 29213221999317397602000, 193993785997407232711875, 1185918539273268050250000, 6720932040786435334078125, 35529086969201421823500000, ...
Projective duality

The projective dual is a hypersurface.

codimension
1
degree
5756196004320
self-dual
no

[Tevelev, Theorems 9.19 and 10.22 (arXiv version)] [Tevelev, Theorems 7.1–7.2 (arXiv version)] All Grassmannians.

Exceptional collections

Full exceptional collections in $\mathbf D^{\mathrm b}(\mathrm{E}_{7}/\mathrm{P}_{2})$:

Quantum cohomology
small
generically semisimple [Holmes–Muratore, Theorems 1.2 and 6.2; Remark 6.3]

Semisimple at $q=1$; $c_1\star$ has the eigenvalue $0$ with algebraic multiplicity 2.

big
generically semisimple [Li–Liu–Yu–Zhang, Theorems 1.2 and 1.4]

Convergent near the large-radius limit.

Eigenvalues of quantum multiplication by $\mathrm{c}_1(\mathrm{E}_{7}/\mathrm{P}_{2})$:

Homological projective duality

No Lefschetz decomposition recorded.

No HP-dual model recorded.

$k$-Fanoness

2-Fano: $\mathrm{ch}_i(\mathrm{T}_{ \mathrm{E}_{7}/\mathrm{P}_{2} })\cdot Z>0$ for every nonzero effective $i$-dimensional cycle $Z$ and $1\leq i\leq 2$. [Araujo et al., Theorems 1.3 and 1.4]

References
  1. Carolina Araujo; Roya Beheshti; Ana-Maria Castravet; Kelly Jabbusch; Svetlana Makarova; Enrica Mazzon; Libby Taylor; Nivedita Viswanathan. Higher Fano Manifolds. Rev. Un. Mat. Argentina 64 (2022), 103–125. arXiv:2110.02339.
  2. Alexander Samokhin; Wilberd van der Kallen. Highest weight category structures on $\operatorname{rep}(B)$ and full exceptional collections on generalized flag varieties over $\mathbb Z$. Preprint (2024). arXiv:2407.13653.
  3. Daniel Holmes; Giosuè Muratore. Effective Gromov–Witten computations for GKM spaces and a semisimple application. Preprint (2026). arXiv:2610.37273.
  4. Changzheng Li; Zhaoyang Liu; Tony Yue Yu; Chi Zhang. Convergence and semisimplicity of big quantum cohomology of flag varieties. Preprint (2026). arXiv:2610.28418.

All references.