986 research outputs found
A Credit Market à la David Hume
In Book III of his Treatise of Human Nature, David Hume considers the following simple interaction: "I suppose a person to have lent me a sum of money, on condition that it be restor'd in a few days, and also suppose, that after the expiration of the term agreed on, he demands the sum" and Hume asks: "What reason or motive have I to restore the money?" [1740, p. 479] The answer, he concludes, must be "that the sense of justice and injustice [which is the motive for repaying the loan] is not deriv'd from nature, but arises artificially, tho' necessarily, from education and human conventions." [p. 483] It is my purpose in this essay to offer formal (and modern) underpinnings for Hume's argument. I shall do so in the context of Hume's own example, cited above, where the interaction being considered is one between lender and borrower.lending, borrowing, credit market
The in-medium isovector pi N amplitude from low energy pion scattering
Differential cross sections for elastic scattering of 21.5 MeV positive and
negative pions by Si, Ca, Ni and Zr have been measured as part of a study of
the pion-nucleus potential across threshold. The `anomalous' repulsion in the
s-wave term was observed, as is the case with pionic atoms. The extra repulsion
can be accounted for by a chiral-motivated model where the pion decay constant
is modified in the medium. Unlike in pionic atoms, the anomaly cannot be
removed by merely introducing an empirical on-shell energy dependence.Comment: 9 pages, 2 figures. Minor changes, to appear in PR
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