In the framework of the theory of open systems based on completely positive quantum dynamical semigroups, we give a description of the continuous-variable quantum correlations (quantum entanglement and quantum discord) for a system consisting of two noninteracting bosonic modes embedded in a thermal environment. We solve the Kossakowski-Lindblad master equation for the time evolution of the con...

We present an analytical solution for classical correlation, defined in terms of linear entropy, in an arbitrary system when the second subsystem is measured. We show that the optimal measurements used in the maximization of the classical correlation in terms of linear entropy, when used to calculate the quantum discord in terms of von Neumann entropy, result in a tight upper bound for arbitrar...

This study examined the associations between the quality of adolescents’ peer and family relationships and the quality of their young adult romantic relationships. Adolescents (N = 253) completed self-report measures of their family and peer relationships in grades 10–12; 7 years later, they reported on connectedness, discord, and the confl ict tactics used by both partners in their current rom...

Depression and marital discord are related to feeling criticized by others, especially by spouses (e.g., Hooley, J. M., & Teasdale, J. D. 1989). This study evaluated the extent to which criticism was overperceived in relation to "actual" spousal critical comments, with actual critical comments being established by independent observers and by criticizing spouses themselves. Using dyadic interac...

Evidence is scarce regarding the prevalence of interparental discord in families of adolescents with attention-deficit hyperactivity disorder (ADHD). Using data collected from adolescents with childhood ADHD and comorbid oppositional-defiant disorder (ODD; n = 46) or conduct disorder (CD; n =23), with childhood ADHD-only (n = 26), and without ADHD (n = 88), and their mothers, maternal and adole...

We introduce the discording power of a unitary transformation, which assesses its capability to produce quantum discord, and analyze in detail the generation of discord by relevant classes of two-qubit gates. Our measure is based on the Cartan decomposition of two-qubit unitaries and on evaluating the maximum discord achievable by a unitary upon acting on classical-classical states at fixed pur...

Nonordered multinomial logistic models were used to estimate the odds of mild and severe husband-to-wife physical aggression in 11,870 White men. Being younger, having a lower income, and having an alcohol problem significantly increased the odds of either mild or severe physical aggression. A drug problem uniquely increased the risk of severe physical aggression. Marital discord and depressive...

In quantum mechanics, observing is not a passive act. Consider a system of two quantum particles A and B: if a measurement apparatus M is used to make an observation on B, the overall state of the system AB will typically be altered. When this happens, no matter which local measurement is performed, the two objects A and B are revealed to possess peculiar correlations known as quantum discord. ...

All suicides (n = 1397) in Finland during 1 year were studied by thorough interviews with the surviving next of kin. We included 388 suicides after which a spouse's or a cohabiting partner's subjective views of precipitant stressors in suicide process during the last 3 months and earlier in life were determined. In 82% of the cases the partner considered life events as precipitant stressors for...