1,240 research outputs found

    Galaxy Counts, Sizes, Colours and Redshifts in the Hubble Deep Field

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    We compare the galaxy evolution models of Bruzual & Charlot (1993) with the faint galaxy count, size and colour data from the Hubble and Herschel Deep Fields (Metcalfe et al 1996). For qo=0.05, we find that models where the SFR increases exponentially out to z>2 are consistent with all of the observational data. For qo=0.5, such models require an extra population of galaxies which are only seen at high redshift and then rapidly fade or disappear. We find that, whatever the cosmology, the redshift of the faint blue galaxies and hence the epoch of galaxy formation is likely to lie at z>2. We find no implied peak in the SFR at z=1 and we suggest that the reasons for this contradiction with the results of Madau et al (1996) include differences in faint galaxy photometry, in the treatment of spiral dust and in the local galaxy count normalisation.Comment: 8 pages, 5 eps figures, needs paspconf.st

    Stability for Borell-Brascamp-Lieb inequalities

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    We study stability issues for the so-called Borell-Brascamp-Lieb inequalities, proving that when near equality is realized, the involved functions must be L1L^1-close to be pp-concave and to coincide up to homotheties of their graphs.Comment: to appear in GAFA Seminar Note

    Nonresonant Contributions in B->rho pi Decay

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    We consider nonresonant contributions in the Dalitz plot analysis of B->rho pi->pi^+ pi^- pi^0 decay and their potential impact on the extraction of the CKM parameter alpha. In particular, we examine the role of the heavy mesons B^* and B_0, via the process B->pi (B^*, B_0)->pi^+ pi^- pi^0, and their interference with resonant contributions in the rho-mass region. We discuss the inherent uncertainties and suggest that the effects may be substantially smaller than previously indicated.Comment: 15 pages, 3 figures; minor changes, version to appear in Phys. Rev.

    The openness conjecture and complex Brunn-Minkowski inequalities

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    We discuss recent versions of the Brunn-Minkowski inequality in the complex setting, and use it to prove the openness conjecture of Demailly and Koll\'ar.Comment: This is an account of the results in arXiv:1305.5781 together with some background material. It is based on a lecture given at the Abel symposium in Trondheim, June 2013. 13 page

    Atomic position localization via dual measurement

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    We study localization of atomic position when a three-level atom interacts with a quantized standing-wave field in the Ramsey interferometer setup. Both the field quadrature amplitude and the atomic internal state are measured to obtain the atomic position information. It is found that this dual measurement scheme produces an interference pattern superimposed on a diffraction-like pattern in the atomic position distribution, where the former pattern originates from the state-selective measurement and the latter from the field measurement. The present scheme results in a better resolution in the position localization than the field-alone measurement schemes. We also discuss the measurement-correlated mechanical action of the standing-wave field on the atom in the light of Popper's test.Comment: 6.5 pages and 5 figure
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