标题： kink-antikink散射引起的呼吸束缚态和振子在参数化的$φ^4$模型中 显示英文标题

标题： Kink-antikink scattering-induced breathing bound states and oscillons in a parametrized $φ^4$ model

摘要： 最近的研究强调了标量场模型中形状可变形性在控制特定类型呼吸束缚态即振子的产生中所起的重要作用，这些标量场模型属于与标准$\phi^4$场同一类。 在宇宙学的背景下，振子的内置机制表明它们可以影响标量超轻暗物质的标准图像。 在本研究中，考虑了一个允许经典$\phi^4$场作为渐近极限的双稳态系统的参数化模型中的孤子散射，重点研究了标量场在真空周围形成寿命较长、振幅较低的近似简谐振荡的形成。 该参数化模型由一个双势阱势构成，其中形状变形参数仅改变势垒壁的陡峭程度，从而改变势垒凸起的平坦度，而不会影响两个简并的最小值和势垒高度。 发现变形参数的变化会在孤子-声子散射势中促进几种额外的振动模式，导致孤子-反孤子散射中的双碰撞窗口被抑制，并产生振子。 数值结果表明，由平坦势垒凸起表征的势垒非简谐性是双势阱系统中振子产生的主要决定因素。 显示英文摘要

摘要： Recent studies have emphasized the important role that a shape deformability of scalar-field models pertaining to the same class with the standard $\phi^4$ field, can play in controlling the production of a specific type of breathing bound states so-called oscillons. In the context of cosmology, the built-in mechanism of oscillons suggests that they can affect the standard picture of scalar ultra-light dark matter. In the present work kink scatterings are investigated in a parametrized model of bistable system admitting the classical $\phi^4$ field as an asymptotic limit, with focus on the formation of long-lived low-amplitude almost harmonic oscillations of the scalar field around a vacuum. The parametrized model is characterized by a double-well potential with a shape-deformation parameter that changes only the steepness of the potential walls, and hence the flatness of the hump of the potential barrier, leaving unaffected the two degenerate minima and the barrier height. It is found that the variation of the deformability parameter promotes several additional vibrational modes in the kink-phonon scattering potential, leading to suppression of the two-bounce windows in kink-antikink scatterings and the production of oscillons. Numerical results suggest that the anharmonicity of the potential barrier, characterized by a flat barrier hump, is the main determinant factor for the production of oscillons in double-well systems.