- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Closing the Door on Quantum Nonlocality
摘要： Bell-type inequalities are proven using oversimpli?ed probabilistic models and/or counterfactual de?niteness (CFD). If setting-dependent variables describing measuring instruments are correctly introduced, none of these inequalities may be proven. In spite of this, a belief in a mysterious quantum nonlocality is not fading. Computer simulations of Bell tests allow people to study the different ways in which the experimental data might have been created. They also allow for the generation of various counterfactual experiments’ outcomes, such as repeated or simultaneous measurements performed in different settings on the same ‘’photon-pair”, and so forth. They allow for the reinforcing or relaxing of CFD compliance and/or for studying the impact of various “photon identi?cation procedures”, mimicking those used in real experiments. Data samples consistent with quantum predictions may be generated by using a speci?c setting-dependent identi?cation procedure. It re?ects the active role of instruments during the measurement process. Each of the setting-dependent data samples are consistent with speci?c setting-dependent probabilistic models which may not be deduced using non-contextual local realistic or stochastic hidden variables. In this paper, we will be discussing the results of these simulations. Since the data samples are generated in a locally causal way, these simulations provide additional strong arguments for closing the door on quantum nonlocality.
关键词： photon identi?cation loophole,Bell-inequalities,quantum nonlocality,local causality,computer simulations of Bell tests,contextuality loophole
更新于2025-09-23 15:21:01
-
On the Kramers-Kronig relations
摘要： We provide a new derivation of the Kramers-Kronig relations on the basis of the Sokhotski-Plemelj equation with detailed mathematical justifications. The relations hold for a causal function, whose Fourier transform is regular (holomorphic) and square-integrable. This implies analyticity in the lower complex plane and a Fourier transform that vanishes at the high-frequency limit. In viscoelasticity, we show that the complex and frequency-dependent modulus describing the stiffness does not satisfy the relation but the modulus minus its high-frequency value does it. This is due to the fact that despite its causality, the modulus is not square-integrable due to a non-null instantaneous response. The relations are obtained in addition for the wave velocity and attenuation factor. The Zener, Maxwell, and Kelvin-Voigt viscoelastic models illustrate these properties. We verify the Kramers-Kronig relations on experimental data of sound attenuation in seabottoms sediments.
关键词： Viscoelasticity,Causality,Zener model,Kramers-Kronig relations,Waves,Sokhotski-Plemelj equation
更新于2025-09-09 09:28:46
-
[IEEE 2018 20th International Conference on Transparent Optical Networks (ICTON) - Bucharest (2018.7.1-2018.7.5)] 2018 20th International Conference on Transparent Optical Networks (ICTON) - The Social-Economic Impact of Fiber Broadband: A Hype or a Reality?
摘要： The social-economic impact of broadband has been studied extensively. The consensus is that basic broadband (from none or upgraded from 256 kbps to the order of 2 – 6 Mbps) indeed has positive impact on economic growth and performance in terms of e.g. GDP and employment. Nevertheless, studies on the social-economic impact of high-speed broadband access (20-30 Mbps and beyond) are far more controversial showing a mixed picture. In this paper, we investigated fiber broadband access impact on the employment rate, population evolution, reduced driving distance per capita and new company registrations at the municipality level in Sweden using multiple regression analysis. Based on the availability of historical fiber network deployment data, analyses can be carried out by regressing current values of social-economic indicators under study on the fiber penetration levels 4 years earlier, hence reverse causality in the regression analyses can be tackled effectively. Our results show that, given all the other significant factors remain the same and with at least 90% confidence interval, 10% increase of fiber broadband penetration would result in 0.17% population increase, 0.32% employment rate enhancement, 28.7 km reduced driving distance per capita per year, and one new company among 17857 inhabitants.
关键词： social-economic impact,causality,social-economic indicators,multiple regression analysis,municipality,fiber broadband penetration
更新于2025-09-09 09:28:46