f(T,𝒯)引力中的夸克星：结构、稳定性与观测约束
Quark Stars in $f(T,\mathcal{T}) $ Gravity: Structure, Stability, and Observational Constraints
AI总结：
该研究在f(T,𝒯)引力框架下，利用MIT袋模型求解夸克星结构方程，发现其最大质量与耦合呈非单调依赖，且在有限正耦合窗口内满足2倍太阳质量脉冲星约束，为超越广义相对论的引力理论提供了观测检验途径。
AI中文摘要：
夸克星是完全由退禁闭夸克物质构成的假想致密星，为检验广义相对论之外的引力理论提供了理想的测试平台。我们在f(T,𝒯)引力（一种平行引力理论，其中挠率通过单一常数耦合直接与能量动量张量的迹耦合）中研究夸克星的结构。采用标准的MIT袋模型描述夸克物质，我们求解修正后的恒星结构方程，并追踪耦合在其全部容许范围内变化时，恒星质量、半径、致密性和表面红移的响应。结果表明，最大质量与耦合呈非单调依赖关系：其值高于广义相对论下的数值，在中等正耦合处达到约2.02倍太阳质量的峰值，随后随耦合趋近于使结构方程奇异的临界值而急剧下降。在有限的正耦合窗口内，该结果满足2倍太阳质量脉冲星约束。候选稳定分支上的所有构型均满足因果性，且始终低于标准广义相对论的致密性和表面红移基准。
英文摘要：
Quark stars-hypothetical compact stars made entirely of deconfined quark matter-offer a clean testing ground for gravity beyond general relativity. We study their structure in $f(T,\mathcal{T})$ gravity, a teleparallel theory in which torsion is coupled directly to the trace of the energy-momentum tensor through a single constant coupling. Using the standard MIT bag description of quark matter, we solve the modified stellar structure equations and follow how the mass, radius, compactness, and surface redshift respond as the coupling is varied across its full admissible range. The maximum mass turns out to depend on the coupling in a non-monotonic way: it rises above the general relativity value, peaks near 2.02 solar masses at a moderate positive coupling, and then falls steeply as the coupling approaches a critical value at which the structure equations become singular. The two-solar-mass pulsar constraint is satisfied within a finite window of positive couplings. All configurations on the candidate stable branch satisfy causality and remain below the standard general-relativistic compactness and surface-redshift benchmarks.
