16,544 research outputs found

    Time-dependent gravitating solitons in five dimensional warped space-times

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    Time-dependent soliton solutions are explicitly derived in a five-dimensional theory endowed with one (warped) extra-dimension. Some of the obtained geometries, everywhere well defined and technically regular, smoothly interpolate between two five-dimensional anti-de Sitter space-times for fixed value of the conformal time coordinate. Time dependent solutions containing both topological and non-topological sectors are also obtained. Supplementary degrees of freedom can be also included and, in this case, the resulting multi-soliton solutions may describe time-dependent kink-antikink systems.Comment: 19 pages, 10 figure

    Universal Properties of Two-Dimensional Boson Droplets

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    We consider a system of N nonrelativistic bosons in two dimensions, interacting weakly via a short-range attractive potential. We show that for N large, but below some critical value, the properties of the N-boson bound state are universal. In particular, the ratio of the binding energies of (N+1)- and N-boson systems, B_{N+1}/B_N, approaches a finite limit, approximately 8.567, at large N. We also confirm previous results that the three-body system has exactly two bound states. We find for the ground state B_3^(0) = 16.522688(1) B_2 and for the excited state B_3^(1) = 1.2704091(1) B_2.Comment: 4 pages, 2 figures, final versio

    Schwinger Boson approach to the fully screened Kondo model

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    We apply the Schwinger boson scheme to the fully screened Kondo model and generalize the method to include antiferromagnetic interactions between ions. Our approach captures the Kondo crossover from local moment behavior to a Fermi liquid with a non-trivial Wilson ratio. When applied to the two impurity model, the mean-field theory describes the "Varma Jones" quantum phase transition between a valence bond state and a heavy Fermi liquid.Comment: 4 pages, 4 figures. Changes to references and text in v

    Gravitating multidefects from higher dimensions

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    Warped configurations admitting pairs of gravitating defects are analyzed. After devising a general method for the construction of multidefects, specific examples are presented in the case of higher-dimensional Einstein-Hilbert gravity. The obtained profiles describe diverse physical situations such as (topological) kink-antikink systems, pairs of non-topological solitons and bound configurations of a kink and of a non-topological soliton. In all the mentioned cases the geometry is always well behaved (all relevant curvature invariants are regular) and tends to five-dimensional anti-de Sitter space-time for large asymptotic values of the bulk coordinate. Particular classes of solutions can be generalized to the framework where the gravity part of the action includes, as a correction, the Euler-Gauss-Bonnet combination. After scrutinizing the structure of the zero modes, the obtained results are compared with conventional gravitating configurations containing a single topological defect.Comment: 27 pages, 5 included figure

    Quantum replica approach to the under-screened Kondo model

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    We extend the Schwinger boson large N treatment of the underscreened Kondo model in a way that correctly captures the finite elastic phase shift in the singular Fermi liquid. The new feature of the approach, is the introduction of a flavor quantum number with K possible values, associated with the Schwinger boson representation. The large N limit is taken maintaining the ratio k=K/N fixed. This approach differs from previous approaches, in that we do not explicitly enforce a constraint on the spin representation of the Schwinger bosons. Instead, the energetics of the Kondo model cause the bosonic degrees of freedom to ``self assemble'' into a ground-state in which the spins of K bosons and N-K conduction electrons are antisymmetrically arranged into a Kondo singlet. With this device, the large N limit can be taken, in such a way that a fraction K/N of the Abrikosov Suhl resonance is immersed inside the Fermi sea. We show how this method can be used to model the full energy dependence of the singular Abrikosov Suhl resonance in the underscreened Kondo model and the field-dependent magnetization.Comment: Revised draft, with plots explicitly showing logarithmic scaling of inverse coupling constant. Small corrections prior to submission to journa

    Decays of metastable vacua in SQCD

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    The decay rates of metastable SQCD vacua in ISS-type models, both towards supersymmetric vacua as well as towards other nonsupersymmetric configurations arising in theories with elementary spectators, are estimated numerically in the semiclassical approximation by computing the corresponding multifield bounce configurations. The scaling of the bounce action with respect to the most relevant dimensionless couplings and ratios of scales is analyzed. In the case of the decays towards the susy vacua generated by nonperturbative effects, the results confirm previous analytical estimations of this scaling, obtained by assuming a triangular potential barrier. The decay rates towards susy vacua generated by R-symmetry breaking interactions turn out to be more than sufficiently suppressed for the phenomenologically relevant parameter range, and their behavior in this regime differs from analytic estimations valid for parametrically small scale ratios. It is also shown that in models with spectator fields, even though the decays towards vacua involving nonzero spectator VEVs don't have a strong parametric dependence on the scale ratios, the ISS vacuum can still be made long-lived in the presence of R-symmetry breaking interactions.Comment: 22 pages, 7 figure

    A Dyadic Analysis of Emotion Regulation as a Moderator of Associations Between Marital Conflict and Marital Satisfaction Among First-married and Remarried Couples

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    We examined emotion regulation strategies as moderators of marital conflict and marital satisfaction between first-married and remarried couples. Remarried couples with a stepchild (n = 108) and first marriage couples (n = 111) with a child completed online surveys. Perceptions of both spouses were analyzed using actor–partner interdependence modeling. Although remarried spouses reported more marital conflict and lower marital satisfaction than first marriage spouses, emotion regulation strategies did not moderate the association between marital conflict and marital satisfaction differently for first-married and remarried couples. Expressive suppression exacerbated the negative association between marital conflict and marital satisfaction for men, and cognitive reappraisal attenuated the negative association for women. There was one partner effect; husbands’ greater cognitive reappraisal buffered the negative association between husbands’ marital conflict and wives’ marital satisfaction. Marriage order was less important than gender in how emotion regulation moderated the associations among marital conflict and marital satisfaction

    Personhood, consciousness, and god : how to be a proper pantheist

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    © Springer Nature B.V. 2018In this paper I develop a theory of personhood which leaves open the possibility of construing the universe as a person. If successful, it removes one bar to endorsing pantheism. I do this by examining a rising school of thought on personhood, on which persons, or selves, are understood as identical to episodes of consciousness. Through a critique of this experiential approach to personhood, I develop a theory of self as constituted of qualitative mental contents, but where these contents are also capable of unconscious existence. On this theory, though we can be conscious of our selves, consciousness turns out to be inessential to personhood. This move, I then argue, provides resources for responding to the pantheist’s problem of God’s person.Peer reviewedFinal Accepted Versio

    Optical study of interactions in a d-electron Kondo lattice with ferromagnetism

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    We report on a comprehensive optical, transport and thermodynamic study of the Zintl compound Yb14_{14}MnSb11_{11}, demonstrating that it is the first ferromagnetic Kondo lattice compound in the underscreened limit. We propose a scenerio whereby the combination of Kondo and Jahn-Teller effects provides a consistent explanation of both transport and optical data.Comment: 4 page

    Local Moments in an Interacting Environment

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    We discuss how local moment physics is modified by the presence of interactions in the conduction sea. Interactions in the conduction sea are shown to open up new symmetry channels for the exchange of spin with the localized moment. We illustrate this conclusion in the strong-coupling limit by carrying out a Schrieffer Wolff transformation for a local moment in an interacting electron sea, and show that these corrections become very severe in the approach to a Mott transition. As an example, we show how the Zhang Rice reduction of a two-band model is modified by these new effects.Comment: Latex file with two postscript figures. Revised version, with more fully detailed calculation
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