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We compute characteristic numbers of crepant resolutions of Weierstrass models corresponding to elliptically fibered fourfolds $Y$ dual in F-theory to a gauge theory with gauge group $G$. In contrast to the case of fivefolds, Chern and Pontryagin numbers of fourfolds are invariant under crepant birational maps. It follows that Chern and Pontryagin numbers are independent on a choice of a crepant resolution. We present the results for the Euler characteristic, the holomorphic genera, the Todd-genus, the $L$-genus, the $hat{A}$-genus, and the curvature invariant $X_8$ that appears in M-theory. We also show that certain characteristic classes are independent on the choice of the Kodaria fiber characterizing the group $G$. That is the case of $int_Y c_1^2 c_2$, the arithmetic genus, and the $hat{A}$-genus. Thus, it is enough to know $int_Y c_2^2$ and the Euler characteristic $chi(Y)$ to determine all the Chern numbers of an elliptically fibered fourfold. We consider the cases of $G=$ SU($n$) for ($n=2,3,4,5,6,7$), USp($4$), Spin($7$), Spin($8$), Spin($10$), G$_2$, F$_4$, E$_6$, E$_7$, or E$_8$.
We compute characteristic numbers of elliptically fibered fourfolds with multisections or non-trivial Mordell-Weil groups. We first consider the models of type E$_{9-d}$ with $d=1,2,3,4$ whose generic fibers are normal elliptic curves of degree $d$.
We introduce special classes of non-commutative crepant resolutions (= NCCR) which we call steady and splitting. We show that a singularity has a steady splitting NCCR if and only if it is a quotient singularity by a finite abelian group. We apply our results to toric singularities and dimer models.
We study crepant resolutions of Weierstrass models of $text{SU}(2)!times!text{SU}(3)$-models, whose gauge group describes the non-abelian sector of the Standard Model. The $text{SU}(2)!times!text{SU}(3)$-models are elliptic fibrations characterized b
In this paper, we study splitting (or toric) non-commutative crepant resolutions (= NCCRs) of some toric rings. In particular, we consider Hibi rings, which are toric rings arising from partially ordered sets, and show that Gorenstein Hibi rings with
In this paper, we study divisorial ideals of a Hibi ring which is a toric ring arising from a partially ordered set. We especially characterize the special class of divisorial ideals called conic using the associated partially ordered set. Using our