The moduli space (M) over bar (0,)n may be embedded into the product of projective spaces P-1 xP(2) x center dot center dot center dot xP(n-3), using a combination of the Kapranov map vertical bar psi(n vertical bar) : (M) over bar (0,)n -> Pn-3 and the forgetful maps pi(i): (M) over bar (0,i) -> (M) over bar (0,i-1). We give an explicit combinatorial formula for the multidegree of this embedding in terms of certain parking functions of height n - 3. We use this combinatorial interpretation to show that the total degree of the embedding (thought of as the projectivization of its cone in A(2) x A(3) center dot center dot center dot x A(n-2)) is equal to (2( n - 3) - 1)!! = (2n - 7)(2n - 9) center dot center dot center dot (5)(3)(1). As a consequence, we also obtain a new combinatorial interpretation for the odd double factorial. (C) 2021 Elsevier Inc. All rights reserved.
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Ohio State Univ, Dept Math, 100 Math Tower,231 West 18TH Ave, Columbus, OH 43210 USAOhio State Univ, Dept Math, 100 Math Tower,231 West 18TH Ave, Columbus, OH 43210 USA
Castravet, Ana-Maria
Tevelev, Jenia
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Univ Massachusetts, Dept Math, Amherst, MA 01003 USAOhio State Univ, Dept Math, 100 Math Tower,231 West 18TH Ave, Columbus, OH 43210 USA