Bao-Min Gu, Yu-Peng Zhang, Fu-Wen Shu, Yu-Xiao Liu
备注：
26 pages, 21 figures, accepted for publication in Physical Review D; substantially revised to include additional analyses of oscillon dynamics and numerical robustness, updated results and figures, and revised interpretations and conclusions
It is well known that, in potentials that are quadratic near the minimum but shallower away, such as small-$α$ ($α\ll M_P^2$) attractors, the inflaton condensate fragments into localized compact objects known as oscillons during self-resonance preheating. In this work, we investigate self-resonance in a deformed $α$-attractor T-model with a Gaussian feature near the minimum, distant from the end of inflation. Linear analysis reveals altered resonance bands and deformed Floquet charts dependent on feature parameters, primarily through the localized modification of $V''(ϕ)$. In fully nonlinear lattice simulations, we find that the potential feature has only a modest influence on gradient-energy transfer during resonance, whereas the subsequent evolution becomes strongly dependent on the Gaussian feature's dimensionless amplitude $h$. Increasing $|h|$ suppresses the formation and persistence of compact oscillons, resulting in fewer objects and a smaller fraction of energy stored in them. The total-energy and internal-gradient-energy diagnostics give consistent lifetime trends. Within the directly resolved range, the oscillon lifetime decreases nonlinearly with increasing $|h|$, with negative $h$ generally producing shorter lifetimes than positive $h$ of the same magnitude. The gravitational wave emission is dominated by the resonant stage and becomes strongly suppressed after oscillon formation. We further find an enhancement in the high-frequency tail of the spectrum, sourced by the potential feature. Although a complete reheating description requires external couplings and higher-resolution simulations, clear qualitative differences in the post-inflationary expansion history already emerge within our simulated time window. These results clarify how potential features affect preheating dynamics and oscillon evolution.
A note on oscillons: non-negligible metric fluctuations during preheating
Jagiellonian University（雅盖隆大学）；University of Utah（犹他大学）；Institute of Science Tokyo（东京科学大学）；University of Portsmouth（朴茨茅斯大学）；Universidade da Beira Interior（伊比利亚大学）
Primordial black holes through preheating instabilities in $α$-attractor models
Universidade da Beira Interior（贝拉内陆大学）；Centro de Matemática e Aplicações da Universidade da Beira Interior（贝拉内陆大学数学与应用中心）；Jagiellonian University（雅盖隆大学）；University of Utah（犹他大学）；Institute of Science Tokyo（东京科学大学）；University of Portsmouth（朴茨茅斯大学）
Decay and lifetime of oscillons coupled to an external scalar field: Insights from instability band analysis
Institute of Science Tokyo（东京科学大学）；Center for Theoretical Physics of the Universe, Institute for Basic Science（基础科学研究院宇宙理论物理中心）；Yonsei University（延世大学）；Tongji University（同济大学）；Institute for Advanced Study of Tongji University（同济大学高等研究院）；Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo Institutes for Advanced Study, The University of Tokyo（东京大学前沿研究机构理化学宇宙物质研究所（WPI））；Yangzhou University（扬州大学）
Scalar-Induced Gravitational Waves from self-resonant preheating in $α$-attractor models
Universidade da Beira Interior（贝拉内陆大学）；Centro de Matemática e Aplicações da Universidade da Beira Interior（贝拉内陆大学数学与应用中心）；University of Utah（犹他大学）；Institute of Science Tokyo（东京科学研究所）；University of Portsmouth（朴茨茅斯大学）
Formation and Decay of Oscillons in Einstein-Cartan Higgs Inflation
Departamento de Física Teórica and Instituto de Física de Partículas y del Cosmos (IPARCOS-UCM), Universidad Complutense de Madrid（马德里康普顿斯大学理论物理系与粒子与宇宙物理研究所(IPARCOS-UCM)）
Gravitational waves from self-resonance during reheating with a quantum-corrected inflaton potential
The University of Tokyo（东京大学）；Shiv Nadar Institution of Eminence (Deemed to be University)（希夫纳达尔卓越学院（视为大学））；RIKEN Center for Interdisciplinary Theoretical and Mathematical Sciences (iTHEMS), RIKEN（理化学研究所交叉理论数学科学中心（iTHEMS））；Yukawa Institute for Theoretical Physics, Kyoto University（京都大学汤川理论物理研究所）
