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Related papers: Introduction to Q-tensor theory

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In this article, we study the new Q-tensor model previously derived from Onsager's molecular theory by Han \textit{et al.} [Arch. Rational Mech. Anal., 215.3 (2014), pp. 741-809] for static liquid crystal modeling. Taking density and…

Soft Condensed Matter · Physics 2015-06-16 Song Mei , Pingwen Zhang

In the mathematical modeling of nematic liquid crystals, a practical and physically reliable $\mathbf{Q}$-tensor model can be derived from Onsager's molecular model with the Bingham closure. However, this procedure leads to a singular…

Soft Condensed Matter · Physics 2026-02-26 Baoming Shi , Dawei Wu , Lei Zhang , Pingwen Zhang

We develop a Q-tensor model of nematic liquid crystals occupying a stationary surface which represents a fluidic material film in space. In addition to the evolution due to Landau--de\,Gennes energy the model includes a tangent viscous…

Fluid Dynamics · Physics 2023-10-06 Lucas Bouck , Ricardo H. Nochetto , Vladimir Yushutin

The properties of liquid crystals can be modelled using an order parameter which describes the variability of the local orientation of rod-like molecules. Defects in the director field can arise due to external factors such as applied…

Numerical Analysis · Mathematics 2019-10-08 Craig S. MacDonald , John A. Mackenzie , Alison Ramage

We use a variational principle to derive a mathematical model for a nematic electrolyte in which the liquid crystalline component is described in terms of a second-rank order tensor. The model extends the previously developed director-based…

In this paper, we propose a systematic way of liquid crystal modeling to build connection between microscopic theory and macroscopic theory. A new Q-tensor theory based on Onsager's molecular theory which leads to liquid crystals with…

Analysis of PDEs · Mathematics 2015-06-16 Jiequn Han , Yi Luo , Wei Wang , Pingwen Zhang

In this article, the fluid-rigid body interaction problem of nematic liquid crystals described by the general Beris-Edwards $Q$-tensor model is studied. It is proved first that the total energy of this problem decreases in time. The…

Analysis of PDEs · Mathematics 2025-09-22 Felix Brandt , Matthias Hieber , Arnab Roy

The goal of this work is to rigorously study the zero inertia limit for the Q-tensor model of liquid crystals. Though present in the original derivation of the Ericksen-Leslie equations for nematic liquid crystals, the inertia term of the…

Numerical Analysis · Mathematics 2024-10-25 Max Hirsch , Franziska Weber , Yukun Yue

This chapter is about the modeling of nematic liquid crystals (LCs) and their numerical simulation. We begin with an overview of the basic physics of LCs and discuss some of their many applications. Next, we delve into the modeling…

Numerical Analysis · Mathematics 2020-01-13 Juan Pablo Borthagaray , Shawn W. Walker

The phenomenological Landau-de Gennes (LdG) model is a powerful continuum theory to describe the macroscopic state of nematic liquid crystals. However, it is invariably less accurate and less physically informed than the molecular-level…

Soft Condensed Matter · Physics 2024-11-20 Baoming Shi , Apala Majumdar , Lei Zhang

We consider the Beris-Edwards system modelling incompressible liquid crystal flows of nematic type. This couples a Navier-Stokes system for the fluid velocity with a parabolic reaction-convection-diffusion equation for the Q-tensors…

Analysis of PDEs · Mathematics 2023-07-28 Hao Wu , Xiang Xu , Arghir Zarnescu

We propose a continuum tensorial model for chiral smectic C (SmC$^*$) liquid crystals using a tensor-valued order parameter $\mathbf{Q}$ to describe orientational order and a real-valued order parameter $\delta\rho$ to capture layer…

Soft Condensed Matter · Physics 2025-09-09 Jingmin Xia , Jinbing Wu , Yucen Han

We construct the molecular model and the tensor model for the dynamics of the nematic phases of bent-core molecules and star molecules in incompressible fluid. We start from the molecular interaction and the molecule--fluid friction, and…

Soft Condensed Matter · Physics 2017-05-09 Jie Xu , Pingwen Zhang

The paper is concerned with various issues surrounding the mathematical description of defects in models of liquid crystals, drawing on experience from solid mechanics. The roles played by a suitable choice of function space and by the…

Analysis of PDEs · Mathematics 2014-11-27 J. M. Ball , S. J. Bedford

We consider a four-elastic-constant Landau-de Gennes energy characterizing nematic liquid crystal configurations described using the $Q$-tensor formalism. The energy contains a cubic term and is unbounded from below. We study dynamical…

Analysis of PDEs · Mathematics 2015-01-22 Gautam Iyer , Xiang Xu , Arghir Zarnescu

In this work, we present three linear numerical schemes to model nematic liquid crystals using the Landau-de Gennes $\textbf{Q}$-tensor theory. The first scheme is based on using a truncation procedure of the energy, which allows for an…

Numerical Analysis · Mathematics 2024-03-27 Justin Swain , Giordano Tierra

A generalized notion of a nonlocal tensor order parameter is introduced within the framework of the phenomenological approach. This parameter has the form of a traceless tensor correlation function or a tensor integral operator. Based on…

Soft Condensed Matter · Physics 2017-07-14 Alexey N. Kudryavtsev , Petr A. Purtov , Sergey I. Trashkeev

We consider a thin film limit of a Landau-de Gennes Q-tensor model. In the limiting process we observe a continuous transition where the normal and tangential parts of the Q-tensor decouple and various intrinsic and extrinsic contributions…

Soft Condensed Matter · Physics 2018-07-04 Ingo Nitschke , Michael Nestler , Simon Praetorius , Hartmut Löwen , Axel Voigt

In this paper, we consider a hydrodynamic $Q$-tensor system for nematic liquid crystal flow, which is derived from Doi-Onsager molecular theory by the Bingham closure. We first prove the existence and uniqueness of local strong solution.…

Analysis of PDEs · Mathematics 2014-10-14 Sirui Li , Wei Wang , Pingwen Zhang

In this paper, we prove the global well posedness and the decay estimates for a $\mathbb Q$-tensor model of nematic liquid crystals in $\mathbb R^N$, $N \geq 3$. This system is coupled system by the Navier-Stokes equations with a…

Analysis of PDEs · Mathematics 2022-03-30 Miho Murata , Yoshihiro Shibata
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