Two of the key properties of quantum physics are the no-signaling principle and the Grover search lower bound. That is, despite admitting stronger-than-classical correlations, quantum mechanics does not imply superluminal signaling, and despite a form of exponential parallelism, quantum mechanics does not imply polynomial-time brute force solution of NP-complete problems. Here, we investigate the degree to which these two properties are connected. We examine four classes of deviations from quantum mechanics, for which we draw inspiration from the literature on the black hole information paradox. We show that in these models, the physical resources required to send a superluminal signal scale polynomially with the resources needed to speed up Grover's algorithm. Hence the no-signaling principle is equivalent to the inability to solve NP-hard problems efficiently by brute force within the classes of theories analyzed.
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http://dx.doi.org/10.1103/PhysRevLett.117.120501 | DOI Listing |
Fluids Barriers CNS
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Department of Neurosurgery, Institute of Brain Diseases, Nanfang Hospital of Southern Medical University, Guangzhou, 510515, China.
Oxidative stress and neuronal apoptosis could be an important factor leading to post-hemorrhagic consequences after germinal matrix hemorrhage (GMH). Previously study have indicated that relaxin 2 receptor activation initiates anti-oxidative stress and anti-apoptosis in ischemia-reperfusion injury. However, whether relaxin 2 activation can attenuate oxidative stress and neuronal apoptosis after GMH remains unknown.
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College of Future Technology, Peking University, Beijing, 100871, China.
Background: SGLT2 inhibitors, a T2DM medication to lower blood glucose, markedly improve cardiovascular outcomes but the underlying mechanism(s) are not fully understood. SGLT2i's produce a unique metabolic pattern by lowering blood glucose without increasing insulin while increasing ketone body and glucagon levels and reducing body weight. We tested if glucagon signaling contributes to SGLT2i induced improvement in CV function.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
October 2024
Institute of Theoretical Physics and Astrophysics, Faculty of Mathematics, Physics and Informatics, University of Gdańsk, Gdańsk 80-308, Poland.
Quantum mechanics imposes limits on the statistics of certain observables. Perhaps the most famous example is the uncertainty principle. Similar trade-offs also exist for the simultaneous violation of multiple Bell inequalities.
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June 2024
Humanities and Arts Department, Technion-Israel Institute of Technology, Haifa 3200003, Israel.
What guarantees the "peaceful coexistence" of quantum nonlocality and special relativity? The tension arises because entanglement leads to locally inexplicable correlations between distant events that have no absolute temporal order in relativistic spacetime. This paper identifies a relativistic consistency condition that is weaker than Bell locality but stronger than the no-signaling condition meant to exclude superluminal communication. While justifications for the no-signaling condition often rely on anthropocentric arguments, relativistic consistency is simply the requirement that joint outcome distributions for spacelike separated measurements (or measurement-like processes) must be independent of their temporal order.
View Article and Find Full Text PDFJ Agric Food Chem
September 2023
Molecular Structure Characterization Unit, RIKEN Center for Sustainable Resource Science, Wako, Saitama 351-0198, Japan.
The cough-suppressing effect of honey was demonstrated for the first time using a guinea pig model whereby cough was induced by citric acid and capsaicin, and a new pyrrolyl pyridoindole, 1-(5-(hydroxymethyl)-1-pyrrol-2-yl)-9-pyrido[3,4-]indole-3-carboxylic acid (), named melpyrrole, and flazin () were identified as the active principle components. The structures of and were estimated using a combination approach of an activity-guided survey and LC-MS/MS multivariate analysis and were finally established by total synthesis of and comparison with an authentic standard for . Both compounds showed antitussive activity comparable to that of dextromethorphan in guinea pigs.
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