Remarks on bell-shaped lumps: stability and fermionic modes

Scattering of metastable lumps in a model with a false vacuum

In this work we consider the scalar field model with a false vacuum proposed by A. T. Avelar, D. Bazeia, L. Losano and R. Menezes, Eur. Phys. J. C 55, 133-143 (2008). The model depends on a parameter $s>0$. The model has unstable nontopological lump solutions with a bell shape for small $s$, acquiring a flat plateau around the maximum for large $s$. For $s\to\infty$ the $ϕ^4$ model is recovered. We show that for $s\gtrsim 2$ the lump is metastable with the only negative mode very close to zero. Metastable lumps can propagate and survive long enough to produce dynamical effects. Due to their si…

平面中非拓扑孤立子的广义模型

Generalized Models for Spinning Field Lumps on Plane

本文提出了一种广义模型，用于研究平面中非拓扑孤立子的稳定性，通过保留薛定谔对称性，在低能下由最低非线性U(1)不变项定义非相对论区域的细节。

Infinite violation of Bell inequalities in inflation

We study the violation of Bell-Mermin-Klyshko (BMK) inequalities in initial quantum states of scalar fields in inflation. We show that the Bell inequality is maximally violated by the Bunch-Davies vacuum which is a two-mode squeezed state of a scalar field. However, we find that the violation of the BMK inequalities does not increase with the number of modes to measure. We then consider a non-Bunch-Davies vacuum expressed by a four-mode squeezed state of two scalar fields. Remarkably, we find that the violation of the BMK inequalities increases exponentially with the number of modes to measure…

通用且最大纠缠交换在一般费米子高斯态中

Universal and Maximal Entanglement Swapping in General Fermionic Gaussian States

本文通过投影贝尔测量在费米子高斯态中实现最大纠缠交换，揭示了费米子统计与高斯性的相互作用，展示了测量诱导最大纠缠的通用机制。