For bipartite quantum states we obtain lower bounds on two important entanglement measures, concurrence and negativity, studying the inequalities for the expectation value of a projector on some subspace of the Hilbert space. Several applications, including analysis of stability of entanglement under various perturbations of a state, are discussed.

中文翻译：

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来自迹不等式的并发性和否定性的下限

对于二分量子态，我们获得了两个重要纠缠度量的下界，即并发性和负性，研究了希尔伯特空间的某个子空间上投影仪的期望值的不等式。讨论了几种应用，包括在状态的各种扰动下分析纠缠的稳定性。