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Qilong Guo

Publications and source records attributed to Qilong Guo.

9 recordsLinked to original sources
arXiv2026

Cofinal towers with vanishing homology torsion

Problem 3.6 in the $\mathrm{K3}$ problem list of Baykur, Kirby and Ruberman asks whether every cofinal tower \[ M_0\longleftarrow M_1\longleftarrow M_2\longleftarrow\cdots \] of finite covers of a finite-volume hyperbolic $3$-manifold satisfies \[ \lim_{n\to\infty} \frac{\log|\operatorname{Tor} H_1(M_n;\mathbb Z)|} {\operatorname{vol}(M_n)} =\frac{1}{6π}. \] We give a negative answer. For every ideal right-angled polyhedron $P_0$, the checkerboard manifold associated to $P_0$ admits a cofinal tower all of whose levels are hyperbolic link complements in $S^3$. Thus $\operatorname{Tor} H_1(M_n;\mathbb Z)=0$ at every level, and the normalized logarithmic homology torsion is identically zero.

math.GT↗
arXiv2026

Unbounded Gaps Between Ordinary and Equivariant Dehn Surgery Numbers

For a closed oriented $3$-manifold $Y$ and an orientation-preserving involution $τ$, let $\DS(Y)$ denote the minimum number of components in an integral surgery description of $Y$, and let $\EDS(Y,τ)$ denote the corresponding minimum among periodic surgery descriptions inducing $τ$. We prove that for every integer $k\geq 1$ there is a pair $(Y_k,τ_k)$ such that \[ \DS(Y_k)=k, \qquad \EDS(Y_k,τ_k)=2k. \] Consequently, the difference $\EDS(Y,τ)-\DS(Y)$ is unbounded even when $τ$ is an involution. This answers Problems~1.15(b) and~1.15(c) in the K3 problem list. We also construct infinitely many pairwise nonhomeomorphic irreducible lens spaces $Z$ admitting involutions $σ$ for which \[ \DS(Z)<\EDS(Z,σ). \]

math.GT↗
arXiv2023

Search for vector-like leptons at a Muon Collider

A feasibility study is performed for searching vector-like leptons at a muon collider, in the context of the "4321 model", an ultraviolet-complete model with rich collider phenomenology together with potential to explain recent existing some B physics measurements or anomalies. In this paper, we perform a Monte Carlo study with various machine learning techniques, and examine the projected sensitivity on vector-like leptons over a wide mass range at a TeV-scale muon collider. We find that a 3 TeV muon collider with only 10/fb of data can already be sensitive to cover the mass range of a vector-like lepton up to 1450 GeV.

hep-ph↗
arXiv2023

On the characteristic length scale for the synthetic turbulence based on the Spalart-Allmaras model

In the hybrid RANS-LES simulations, proper turbulent fluctuations should be added at the RANS-to-LES interface to drive the numerical solution restoring to a physically resolved turbulence as rapidly as possible. Such turbulence generation methods mostly need to know the distribution of the characteristic length scale of the background RANS model, which is important for the recovery process. The approximation of the length scale for the Spalart-Allmaras (S-A) model is not a trivial issue since the model's one-equation nature. As a direct analogy, the approximations could be obtained from the definition of the Prandtl's mixing length. Moreover, this paper proposes a new algebraic expression to approximate the intrinsic length scale of the S-A model. The underlying transportation mechanism of S-A model are largely exploited in the derivation of this new expression. The new proposed expression is employed in the generation of synthetic turbulence to perform the hybrid RANS-LES simulation of canonical wall-bounded turbulent flows. The comparisons demonstrated the feasibility and improved performance of the new length scale on generating synthetic turbulence at the LES inlet.

physics.flu-dyn↗
arXiv2022

Analysis of Wall Heat Flux of a Hypersonic Shock Wave / Boundary Layer Interaction with a Novel Decomposition Formula

The generation mechanism of wall heat flux is one of the fundamental problems in supersonic/hypersonic turbulent boundary layers. A novel heat decomposition formula under the curvilinear coordinate was proposed in this paper. The new formula has wider application scope and can be applied in the configurations with grid deformed. The wall heat flux of an interaction between shock wave and the turbulent boundary layer over a compression corner is analyzed by the new formula. The results indicated good performance of the formula in the complex interaction region. The contributions of different energy transport processes were obtained. The contributions by the turbulent fluctuations e.g., Reynolds stresses and turbulent transport of heat flux, were significantly increased, while the processes by the mean profile e.g., molecular stresses and heat conduction, can be neglected. In addition, the pressure work is another contributor to the wall heat flux and the streamwise component works mainly in the shear layer and the reattachment point, while pressure in the wall-normal direction is concentrated in the vicinity of the reattachment point.

physics.flu-dyn↗
arXiv2021

Decomposition Formula for the Wall Heat Flux of a Compressible Boundary Layer

Understanding the generation mechanism of the heating flux is essential for the design of hypersonic vehicles. We proposed a novel formula to decompose the heat flux coefficient into the contributions of different terms by integrating the conservative equation of the total energy. The reliability of the formula is well demonstrated by the direct numerical simulation results of a hypersonic transitional boundary layer. Through this formula, the exact process of the energy transport in the boundary layer can be explained and the dominant contributors to the heat flux can be explored, which are beneficial for the prediction of the heat and design of the thermal protection devices

physics.flu-dyn↗
arXiv2017

Width of a satellite knot and its companion

In the paper we prove the conjecture by Alexander Zupan that $w(K) \geqslant n^2w(J)$ where w denote the width and $K$ and $J$ are satellite knot and its companion with winding number $n$. Also we proved that for satellite knot with braid pattern, the equality holds.

math.GT↗
arXiv2013

The Heegaard distances cover all non-negative integers

In this paper, we prove that (1) For any integers $n\geq 1$ and $g\geq 2$, there is a closed 3-manifold $M_{g}^{n}$ which admits a distance $n$ Heegaard splitting of genus $g$ except that the pair of $(g, n)$ is $(2, 1)$. Furthermore, $M_{g}^{n}$ can be chosen to be hyperbolic except that the pair of $(g, n)$ is $(3, 1)$. (2) For any integers $g\geq 2$ and $n\geq 4$, there are infinitely many non-homeomorphic closed 3-manifolds admitting distance $n$ Heegaard splittings of genus $g$.

math.GT↗