Anomalous response in the vicinity of spontaneous symmetry breaking

We propose a mechanism to induce negative AC permittivity in the vicinity of a ferroelectric phase transition involved with spontaneous symmetry breaking. This mechanism makes use of responses at low frequency, yielding a high gain and a large phase delay, when the system jumps over the free-energy barrier with the aid of external fields. We illustrate the mechanism by analytically studying spin models with the Glauber-typed dynamics under periodic perturbations. Then, we show that the scenario is supported by numerical simulations of mean-field as well as two-dimensional spin systems.Comment: 6 pages, 5 figure

Experimental and numerical investigation on the structural performance of the tensioning air beam system

An experimental and numerical study on the structural performance of the tensioning air beam system (TABS) is presented. TABS is a hybrid structural system consisting of a membrane air beam, steel frames and cable struts. This system has the advantage of reduced self-weight and is easy to construct while it can improve the load bearing capacity of membrane structures. It maximizes the structural capacities of individual elements, thus can be considered as a very effective system in terms of both structural and economical aspects. In this paper, a test was carried out to examine the structural performance of TABS under different membrane pressure conditions. The material properties of the air beam were obtained from the results of two membrane tensile strength tests, which were performed prior to the main test. A simple numerical model was proposed to predict the structural behavior of TABS and its validity was evaluated by comparing its results with the test values

Neural Spectro-polarimetric Fields

Modeling the spatial radiance distribution of light rays in a scene has been extensively explored for applications, including view synthesis. Spectrum and polarization, the wave properties of light, are often neglected due to their integration into three RGB spectral bands and their non-perceptibility to human vision. Despite this, these properties encompass substantial material and geometric information about a scene. In this work, we propose to model spectro-polarimetric fields, the spatial Stokes-vector distribution of any light ray at an arbitrary wavelength. We present Neural Spectro-polarimetric Fields (NeSpoF), a neural representation that models the physically-valid Stokes vector at given continuous variables of position, direction, and wavelength. NeSpoF manages inherently noisy raw measurements, showcases memory efficiency, and preserves physically vital signals, factors that are crucial for representing the high-dimensional signal of a spectro-polarimetric field. To validate NeSpoF, we introduce the first multi-view hyperspectral-polarimetric image dataset, comprised of both synthetic and real-world scenes. These were captured using our compact hyperspectral-polarimetric imaging system, which has been calibrated for robustness against system imperfections. We demonstrate the capabilities of NeSpoF on diverse scenes