Log-TQFT and torsion

A QFT for non-semisimple TQFT

We construct a family of 3d quantum field theories $\mathcal T_{n,k}^A$ that conjecturally provide a physical realization -- and derived generalization -- of non-semisimple mathematical TQFT's based on the modules for the quantum group $U_q(\mathfrak{sl}_n)$ at an even root of unity $q=\text{exp}(iπ/k)$. The theories $\mathcal T_{n,k}^A$ are defined as topological twists of certain 3d $\mathcal N=4$ Chern-Simons-matter theories, which also admit string/M-theory realizations. They may be thought of as $SU(n)_{k-n}$ Chern-Simons theories, coupled to a twisted $\mathcal N=4$ matter sector (the so…

确定性超树的同调扭转增长

The homology torsion growth of determinantal hypertrees

研究确定性超树的同调群增长特性，证明其扭转增长常数范围。

Hadamard Matrix Torsion

We construct a series HMT$(n)$ of $2$-dimensional simplicial complexes with torsion $H_1($HMT$(n))=(\mathbb{Z}_2)^{{k}\choose{1}} \times (\mathbb{Z}_4)^{{k}\choose{2}} \times \cdots \times (\mathbb{Z}_{2^k})^{{k}\choose{k}}$, $|H_1($HMT$(n))|=|$det(H$(n))|=n^{n/2} \in Θ(2^{n \log n})$, where the construction is based on the Hadamard matrices H$(n)$ for $n\geq 2$ a power of $2$, i.e., $n=2^k, \ k \geq 1$. The examples have linearly many vertices, their face vector is $f(HMT(n))=(5n-1,3n^2+9n-6,3n^2+4n-4)$. Our explicit series with torsion growth in $Θ(2^{n \log n})$ is constructed in quadratic …

Higher even dimensional Reidemeister torsion for torus knot exteriors

We study the asymptotics of the higher dimensional Reidemeister torsion for torus knot exteriors, which is related to the results by W. Müller and P. Menal-Ferrer and J. Porti on the asymptotics of the Reidemeister torsion and the hyperbolic volumes for hyperbolic 3-manifolds. We show that the sequence of log |the higher dimensional Reidemeister torsion of a torus knot exterior with SL(2N,C)-representation| / (2N)^2 converges to zero when N goes to infinity. We also give a classification for SL(2,C)-representations of torus knot groups, which induce acyclic SL(2N,C)-representations.

Higher dimensional Reidemeister torsion invariants for cusped hyperbolic 3-manifolds

For an oriented finite volume hyperbolic 3-manifold M with a fixed spin structure η, we consider a sequence of invariants {τ_n(M; η)}. Roughly speaking, {τ_n(M; η)} is the Reidemeister torsion of M with respect to the representation given by the composition of the lift of the holonomy representation defined by η, and the n-dimensional, irreducible, complex representation of SL(2,C). In the present work, we focus on two aspects of this invariant: its asymptotic behavior and its relationship with the complex-length spectrum of the manifold. Concerning the former, we prove that for suitable spin …

廉价嵌入原理：同调增长的动力学上界

The cheap embedding principle: Dynamical upper bounds for homology growth

本文在度量群论框架下，为群的对数挠同调增长和贝蒂数增长建立了动力学上界。