Information erasure and the generalized second law of black hole thermodynamics

We consider the generalized second law of black hole thermodynamics in the light of quantum information theory, in particular information erasure and Landauer’s principle (namely, that erasure of information produces at least the equivalent amount of entropy). A small quantum system outside a black hole in the Hartle-Hawking state is studied, and the quantum system comes into thermal equilibrium with the radiation surrounding the black hole. For this scenario, we present a simple proof of the generalized second law based on quantum relative entropy. We then analyze the corresponding information erasure process, and confirm our proof of the generalized second law by applying Landauer’s principle

G\"odel Incompleteness and the Black Hole Information Paradox

Semiclassical reasoning suggests that the process by which an object collapses into a black hole and then evaporates by emitting Hawking radiation may destroy information, a problem often referred to as the black hole information paradox. Further, there seems to be no unique prediction of where the information about the collapsing body is localized. We propose that the latter aspect of the paradox may be a manifestation of an inconsistent self-reference in the semiclassical theory of black hole evolution. This suggests the inadequacy of the semiclassical approach or, at worst, that standard quantum mechanics and general relavity are fundamentally incompatible. One option for the resolution for the paradox in the localization is to identify the G\"odel-like incompleteness that corresponds to an imposition of consistency, and introduce possibly new physics that supplies this incompleteness. Another option is to modify the theory in such a way as to prohibit self-reference. We discuss various possible scenarios to implement these options, including eternally collapsing objects, black hole remnants, black hole final states, and simple variants of semiclassical quantum gravity.Comment: 14 pages, 2 figures; revised according to journal requirement

Interacting Agegraphic Dark Energy

A new dark energy model, named "agegraphic dark energy", has been proposed recently, based on the so-called K\'{a}rolyh\'{a}zy uncertainty relation, which arises from quantum mechanics together with general relativity. In this note, we extend the original agegraphic dark energy model by including the interaction between agegraphic dark energy and pressureless (dark) matter. In the interacting agegraphic dark energy model, there are many interesting features different from the original agegraphic dark energy model and holographic dark energy model. The similarity and difference between agegraphic dark energy and holographic dark energy are also discussed.Comment: 10 pages, 5 figures, revtex4; v2: references added; v3: accepted by Eur. Phys. J. C; v4: published versio

Views of young, rural African Americans of the role of community social institutions in HIV prevention.

BACKGROUND: We explored rural African American youths' perceptions about the role of community social institutions in addressing HIV. METHODS: We conducted four focus groups with African Americans aged 16 to 24 years in two rural counties in North Carolina. Groups were stratified by gender and risk status. We used a grounded theory approach to content analysis. RESULTS: Participants identified four social institutions as primary providers of HIV-related health promotion efforts: faith organizations, schools, politicians, and health agencies. They reported perceiving a lack of involvement in HIV prevention by faith-based organizations, constraints of abstinence-based sex education policies, politicians' lack of interest in addressing broader HIV determinants, and inadequacies in health agency services, and viewed all of these as being counter-productive to HIV prevention efforts. CONCLUSIONS: Youth have important insights about local social institutions that should be considered when designing HIV prevention interventions that partner with local organizations

Comparing research priority-setting partnerships for older adults across international health care systems: a systematic review

OBJECTIVES: Priority setting partnerships (PSPs) attempt to shape the research agenda to address the needs of local populations of interest. We reviewed the PSPs for older adults, with a focus on exemplar health care systems: United Kingdom (UK; publicly funded), United States (private health insurance-based), South Korea (national health insurance-based), and Africa (out-of-pocket). DESIGN: Systematic review. SETTING AND PARTICIPANTS: We searched databases and sources (January 2011-October 202l; updated in February 2023) for PSPs of older adults' health care. METHODS: Based on the British geriatric medicine curriculum, we extracted and categorized the PSP topics by areas and the research priorities by themes, and generated evidence maps depicting and comparing the research gaps across the systems. We evaluated PSP quality using the Nine Common Themes of Good Clinical Practice. RESULTS: We included 32 PSPs (United Kingdom: n = 25; United States: n = 7; South Korea and Africa: n = 0) and identified priorities regarding 27 conditions or service arrangements in the United Kingdom and 9 in the United States (predominantly in neurology/psychiatry). The UK priorities focused on treatments and interventions whereas the US on prognostic/predictive factors. There were notable research gaps within the existing PSPs, including common geriatric conditions like continence and frailty. The PSP quality evaluation revealed issues around lacking inclusion of ethnic minorities. CONCLUSIONS AND IMPLICATIONS: Research priorities for older adult health care vary internationally, but certain health care systems/countries have no available PSPs. Where PSPs are available, fundamental aspects of geriatric medicine have not been included. Future researchers should conduct prioritizations in different countries, focus on core geriatric syndromes, and ensure the inclusion of all relevant stakeholder groups

Cosmic Background Bose Condensation (CBBC)

Degeneracy effects for bosons are more important for smaller particle mass, smaller temperature and higher number density. Bose condensation requires that particles be in the same lowest energy quantum state. We propose a cosmic background Bose condensation, present everywhere, with its particles having the lowest quantum energy state, A c/lambda, with lambda about the size of the visible universe, and therefore unlocalized. This we identify with the quantum of the self gravitational potential energy of any particle, and with the bit of information of minimum energy. The entropy of the universe (similar to 10(122) bits) has the highest number density (similar to 10(36) bits/cm(3)) of particles inside the visible universe, the smallest mass, similar to 10(-66) g, and the smallest temperature, similar to 10(-29) K. Therefore it is the best candidate for a Cosmic Background Bose Condensation (CBBC), a completely calmed fluid, with no viscosity, in a superfluidity state, and possibly responsible for the expansion of the universe.Alfonso-Faus, A.; Fullana Alfonso, MJ. (2013). Cosmic Background Bose Condensation (CBBC). Astrophysics and Space Science. 347(1):193-196. doi:10.1007/s10509-013-1500-8S1931963471Alfonso-Faus, A.: Universality of the self gravitational potential energy of any fundamental particle. Astrophys. Space Sci. 337, 363 (2010a)Alfonso-Faus, A.: The case for the Universe to be a quantum black hole. Astrophys. Space Sci. 325, 113 (2010b)Alfonso-Faus, A.: Galaxies: kinematics as a proof of the existence of a universal field of minimum acceleration. arXiv:0708.0308 (2010c, preprint)Alfonso-Faus, A.: Quantum gravity and information theories linked by the physical properties of the bit. arXiv:1105.3143 (2011, preprint)Anderson, J.D., et al.: Indication, from Pioneer 10/11, Galileo, and Ulysses data, of an apparent anomalous, weak, long-range acceleration. Phys. Rev. Lett. 81, 2858 (1998)Bekenstein, J.D.: Phys. Rev. D 23(2), 287 (1981)Bérut, A., et al.: Experimental verification of Landauer’s principle linking information and thermodynamics. Nature 483, 187 (2012)Drees, M., Chung-Lin, S.: Theoretical interpretation of experimental data from direct dark matter detection. J. Cosmol. Astropart. Phys. 0706, 011 (2007)Eisberg, R., Resnick, R.: Quantum Physics of Atoms, Molecules, Solids, Nuclei and Particles, 2nd edn. Wiley, New York (1985)Funo, K., Watanabe, Y., Ueda, M.: Thermodynamic work gain from entanglement. arXiv:1207.6872 [quant-ph] (2012, preprint)Hawking, S.W.: Black hole explosions? Nature 248, 30 (1974)Landauer, R.: Irreversibility and heat generation in the computing process. IBM J. Res. Dev. 5, 183 (1961)Landauer, R.: Dissipation and noise immunity in computation and communication. Nature 335, 779 (1988)Lloyd, S.: Computational capacity of the universe. Phys. Rev. Lett. 88, 237901 (2002)Misner, C.W., Thorne, K.S., Wheeler, J.A.: Gravitation. Freeman, Reading (1973), p. 466 (“Why the energy of the gravitational field cannot be localized”)Scarpa, R., Falomo, R.: Testing Newtonian gravity in the low acceleration regime with globular clusters: the case of omega Centauri revisited. Astron. Astrophys. 523, A43 (2010)Sivaram, C.: Cosmological and quantum constraint on particle masses. Am. J. Phys. 50, 279 (1982)Susskind, L.: The World as a hologram. J. Math. Phys. 36, 6377 (1995)’t Hooft, G.: Dimensional reduction in quantum gravity. arXiv:gr-qc/9310026 (1993, preprint)Toyabe, S., et al.: Experimental demonstration of information-to-energy conversion and validation of the generalized Jarzynski equality. Nat. Phys. 6, 988 (2010)Unruh, W.G.: Notes on black-hole evaporation. Phys. Rev. D, Part. Fields 14(4), 870 (1976)Weinberg, S.: Gravitation and Cosmology: Principles and Applications of the General Theory of Relativity p. 619. Wiley, New York (1972

The Physiology of Vasodilatation

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68237/2/10.1177_000331976101200602.pd

Many body physics from a quantum information perspective

The quantum information approach to many body physics has been very successful in giving new insight and novel numerical methods. In these lecture notes we take a vertical view of the subject, starting from general concepts and at each step delving into applications or consequences of a particular topic. We first review some general quantum information concepts like entanglement and entanglement measures, which leads us to entanglement area laws. We then continue with one of the most famous examples of area-law abiding states: matrix product states, and tensor product states in general. Of these, we choose one example (classical superposition states) to introduce recent developments on a novel quantum many body approach: quantum kinetic Ising models. We conclude with a brief outlook of the field.Comment: Lectures from the Les Houches School on "Modern theories of correlated electron systems". Improved version new references adde

A measurement of the tau mass and the first CPT test with tau leptons

We measure the mass of the tau lepton to be 1775.1+-1.6(stat)+-1.0(syst.) MeV using tau pairs from Z0 decays. To test CPT invariance we compare the masses of the positively and negatively charged tau leptons. The relative mass difference is found to be smaller than 3.0 10^-3 at the 90% confidence level.Comment: 10 pages, 4 figures, Submitted to Phys. Letts.

First Measurement of Z/gamma* Production in Compton Scattering of Quasi-real Photons

We report the first observation of Z/gamma* production in Compton scattering of quasi-real photons. This is a subprocess of the reaction e+e- to e+e-Z/gamma*, where one of the final state electrons is undetected. Approximately 55 pb-1 of data collected in the year 1997 at an e+e- centre-of-mass energy of 183 GeV with the OPAL detector at LEP have been analysed. The Z/gamma* from Compton scattering has been detected in the hadronic decay channel. Within well defined kinematic bounds, we measure the product of cross-section and Z/gamma* branching ratio to hadrons to be (0.9+-0.3+-0.1) pb for events with a hadronic mass larger than 60 GeV, dominated by (e)eZ production. In the hadronic mass region between 5 GeV and 60 GeV, dominated by (e)egamma* production, this product is found to be (4.1+-1.6+-0.6) pb. Our results agree with the predictions of two Monte Carlo event generators, grc4f and PYTHIA.Comment: 18 pages, LaTeX, 5 eps figures included, submitted to Physics Letters