81 citations · 856 across the 43 of their papers we have counts for
44 papers
Holonomy Reconstruction and Character Varieties of Lorentzian Curved Tetrahedra
Hongguang Liu, Qiaoyin Pan
We give a recognition and reconstruction theorem for finite strictly convex tetrahedra in and with spacelike, timelike, or null faces. The input consists…
Probing mass inflation in polymerized vacuum regular black holes via colliding null shells
Hongguang Liu, Ioannis Soranidis
We derive a class of inner-extremal regular black hole solutions characterized by a degenerate inner horizon. These geometries arise as polymerized vacuum configurations inspired b…
Asymptotic Symmetries of the Holst Action at Spatial Infinity: Including Supertranslations
Sepideh Bakhoda, Hongguang Liu
We investigate the asymptotic symmetries of General Relativity at spatial infinity within the first-order formalism described by the Holst action. Employing the covariant phase spa…
Regular ultracompact objects with anti-de Sitter cores as polymerized vacuum solutions
Hongguang Liu, Ioannis Soranidis
We present a systematic derivation of regular black hole solutions -- and their horizonless counterparts -- that achieve regularization via an anti-de Sitter core. These geometries…
Bridging Quantum and Semiclassical Volume: A Numerical Study of Coherent State Matrix Elements in Loop Quantum Gravity
Haida Li, Hongguang Liu
In Loop Quantum Gravity, the quantum action of the volume operator is crucial in understanding quantum dynamics. In this work, we implement a generalized numerical algorithm that c…
Beyond Expectation Values: Generalized Semiclassical Expansions for Matrix Elements of Gauge Coherent States
Haida Li, Hongguang Liu
We derive an asymptotic expansion for off-diagonal coherent-state matrix elements of non-polynomial operators in gauge theories admitting holomorphic coherent-state representations…
Quantum induced shock dynamics in gravitational collapse: insights from effective models and numerical frameworks
Hongguang Liu, Dongxue Qu
We explore the formation and evolution of shock waves in spherically symmetric gravitational collapse within a Loop Quantum Gravity (LQG) inspired effective framework. In this sett…
The one-loop effective action from the coherent state path integral of loop quantum gravity
Renata Ferrero, Muxin Han, Hongguang Liu
We adopt a novel approach to combine path integral methods with Loop Quantum Gravity (LQG). Our approach builds upon the recently developed coherent state path integral formulation…
Properties of 4D spinfoam quantum geometry: Results from next-to-leading order spinfoam large- asymptotics of 1-5 Pachner move
Haida Li, Muxin Han, Hongguang Liu +2
This paper proposes several criteria to probe the non-trivialities of 4-dimensional geometry that impact spinfoam amplitude. These criteria include the standard deviation of 4-volu…
A Mathematica program for numerically computing real and complex critical points in 4-dimensional Lorentzian spinfoam amplitude
Muxin Han, Hongguang Liu, Dongxue Qu
This work develops a comprehensive algorithm and a Mathematica program to construct boundary data and compute real and complex critical points in spinfoam amplitudes. Our approach…
Cosmological Dynamics from Covariant Loop Quantum Gravity with Scalar Matter
Muxin Han, Hongguang Liu, Dongxue Qu +2
We study homogenous and isotropic quantum cosmology using the spinfoam formalism of Loop Quantum Gravity (LQG). We define a coupling of a scalar field to the 4-dimensional Lorentzi…
Generalized analysis of a dust collapse in effective loop quantum gravity: fate of shocks and covariance
Kristina Giesel, Hongguang Liu, Parampreet Singh +1
Based on modifications inspired from loop quantum gravity (LQG), spherically symmetric models have recently been explored to understand the resolution of classical singularities an…
Embedding generalized LTB models in polymerized spherically symmetric spacetimes
Kristina Giesel, Hongguang Liu, Eric Rullit +2
We generalize the existing works on the way (generalized) LTB models can be embedded into polymerized spherically symmetric models in several aspects. We re-examine such an embeddi…
Dynamically implementing the -scheme in cosmological and spherically symmetric models in an extended phase space model
Kristina Giesel, Hongguang Liu
We consider an extended phase space formulation for cosmological and spherically symmetric models in which the choice of a given -scheme can be implemented dynamically.…
Complex critical points in Lorentzian spinfoam quantum gravity: 4-simplex amplitude and effective dynamics on double- complex
Muxin Han, Hongguang Liu, Dongxue Qu
The complex critical points are analyzed in the 4-dimensional Lorentzian Engle-Pereira-Rovelli-Livine (EPRL) spinfoam model in the large- regime. For the 4-simplex amplitude, ta…
Spinfoams and high performance computing
Pietro Dona, Muxin Han, Hongguang Liu
Numerical methods are a powerful tool for doing calculations in spinfoam theory. We review the major frameworks available, their definition, and various applications. We start from…
Covariant -scheme effective dynamics, mimetic gravity, and non-singular black holes: Applications to spherical symmetric quantum gravity and CGHS model
Muxin Han, Hongguang Liu
We propose a new -scheme Hamiltonian effective dynamics in the spherical symmetric sector of Loop Quantum Gravity (LQG). The effective dynamics is generally covariant as der…
Spherical symmetric gravitational collapse of a dust cloud: polymerized dynamics in reduced phase space
Kristina Giesel, Muxin Han, Bao-Fei Li +2
Based on the effective dynamics in the scheme of the spherical symmetry reduced model in the reduced phase space formulation of loop quantum gravity (LQG), we investigate…
Fermions in Loop Quantum Gravity and Resolution of Doubling Problem
Cong Zhang, Hongguang Liu, Muxin Han
The fermion propagator is derived in detail from the model of fermion coupled to loop quantum gravity. As an ingredient of the propagator, the vacuum state is defined as the ground…
Experimental Simulation of Loop Quantum Gravity on a Photonic Chip
Reinier van der Meer, Zichang Huang, Malaquias Correa Anguita +6
The unification of general relativity and quantum theory is one of the fascinating problems of modern physics. One leading solution is Loop Quantum Gravity (LQG). Simulating LQG ma…
Fermions on Quantum Geometry and Resolution of Doubling Problem
Cong Zhang, Hongguang Liu, Muxin Han
The fermion doubling problem has an important impact on quantum gravity, by revealing the tension between fermion and the fundamental discreteness of quantum spacetime. In this wor…
Complex critical points and curved geometries in four-dimensional Lorentzian spinfoam quantum gravity
Muxin Han, Zichang Huang, Hongguang Liu +1
This paper focuses on the semiclassical behavior of the spinfoam quantum gravity in 4 dimensions. There has been long-standing confusion, known as the flatness problem, about wheth…
Finiteness of spinfoam vertex amplitude with timelike polyhedra, and the full amplitude
Muxin Han, Wojciech Kaminski, Hongguang Liu
This work focuses on Conrady-Hnybida's 4-dimensional extended spinfoam model with timelike polyhedra, while we restrict all faces to be spacelike. Firstly, we prove the absolute co…
Analytic Continuation of Spin foam Models
Muxin Han, Hongguang Liu
The Lorentzian Engle-Pereira-Rovelli-Livine/Freidel-Krasnov (EPRL/FK) spinfoam model and the Conrady-Hnybida (CH) timelike-surface extension can be expressed in the integral form $…