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We present a simple and natural dark sector model in which dark matter particles arise as composite states of hidden strong dynamics and their stability is ensured by accidental symmetries. The model has only a few free parameters. In particular, the gauge symmetry of the model forbids the masses of dark quarks, and the confinement scale of the dynamics provides the unique mass scale of the model. The gauge group contains an Abelian symmetry U(1)_{D}, which couples the dark and standard model sectors through kinetic mixing. This model, despite its simple structure, has rich and distinctive phenomenology. In the case where the dark pion becomes massive due to U(1)_{D} quantum corrections, direct and indirect detection experiments can probe thermal relic dark matter which is generically a mixture of the dark pion and the dark baryon, and the Large Hadron Collider can discover the U(1)_{D} gauge boson. Alternatively, if the dark pion stays light due to a specific U(1)_{D} charge assignment of the dark quarks, then the dark pion constitutes dark radiation. The signal of this radiation is highly correlated with that of dark baryons in dark matter direct detection.
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We propose a simple mechanism to suppress axion isocurvature fluctuations using hidden sector magnetic monopoles. This allows for the Peccei-Quinn scale to be of the order of the unification scale consistently with high scale inflation.
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We discuss the interior of a black hole in quantum gravity, in which black holes form and evaporate unitarily. The interior spacetime appears in the sense of complementarity because of special features revealed by the microscopic degrees of freedom when viewed from a semiclassical standpoint. The relation between quantum mechanics and the equivalence principle is subtle, but they are still consistent.
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We argue that under a set of simple assumptions the multiverse leads to low-energy supersymmetry with the spectrum often called spread or minisplit supersymmetry: the gauginos are in the TeV region with the other superpartners 2 or 3 orders of magnitude heavier. We present a particularly simple realization of supersymmetric grand unified theory using this idea.
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PURPOSE: To determine whether significant correlations existed between the morphological and functional parameters of the macular region of eyes with open-angle glaucoma (OAG). METHODS: Forty eyes of 40 OAG patients were studied. The morphological parameters were obtained by optical coherence tomography (OCT), and the functional parameters were acquired by automated Humphrey Field Analyzer (HFA) and multifocal electroretinograms (mfERGs). All of the tests were performed within 6 months of each other. The retinal thickness was determined by OCT in the nine Early Treatment of Diabetic Retinopathy Study (ETDRS) sectors of the macula, the fovea, and the four quadrants of the inner and an outer ring. The amplitudes of the second-order kernel responses of the mfERGs in the central 5° including the amplitude ratio of the nasal to temporal hemispheres (N/T amplitude ratio) were analyzed. The total mean deviation of the HFA corresponding to each OCT region was measured. The correlation between the different parameters was determined by coefficients of correlation and linear regression analyses. RESULTS: The N/T amplitude ratio of the second-order kernel responses of the mfERGs was significantly correlated with the retinal thickness in the inferior quadrant (r = -0.44; P = 0.004). There was a significant correlation between the N/T amplitude ratio and the threshold in the superior quadrant measured by the HFA Central 10-2 program (r = -0.40; P = 0.011) and also between the N/T amplitude ratio and the total deviation in the superior quadrant (r = -0.40; P = 0.010). There were significant correlations between the inferior retinal thickness and the average threshold and the TD in superior (r = 0.70, P < 0.001; r = 0.692, P < 0.001, respectively), nasal (r = 0.53, P < 0.001; r = 0.53, P < 0.001, respectively), and temporal (r = 0.46, P = 0.003; r = 0.44, P = 0.004, respectively) quadrants. CONCLUSIONS: Functional glaucomatous changes determined by mfERGs and perimetry are significantly correlated with the morphological changes determined by OCT.
Assuntos
Eletrorretinografia , Glaucoma de Ângulo Aberto/fisiopatologia , Retina/fisiopatologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Humanos , Pressão Intraocular/fisiologia , Masculino , Pessoa de Meia-Idade , Fibras Nervosas , Células Ganglionares da Retina , Tomografia de Coerência Óptica , Testes de Campo Visual , Campos Visuais/fisiologiaRESUMO
We present a new approach to the microBmicro problem of gauge-mediated supersymmetry breaking. Rather than reducing the generically large contribution to Bmicro we point out that acceptable electroweak symmetry breaking can be achieved with micro{2}<
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Gauge mediation of supersymmetry breaking is drastically simplified using generic superpotentials without U(1)R symmetry by allowing metastable vacua.
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Theories of evolving quintessence are constructed that generically lead to deviations from the w = -1 prediction of nonevolving dark energy. The small mass scale that governs evolution, m(phi) approximately = 10(-33) eV, is radiatively stable, and the "Why now?" problem is solved. These results rest on seesaw cosmology: Fundamental physics and cosmology can be broadly understood from only two mass scales, the weak scale nu and the Planck scale M. Requiring a scale of dark energy rho(DE)(1/4) governed by nu2/M and a radiatively stable evolution rate m(phi) given by nu4/M3 leads to a distinctive form for the equation of state w(z). Dark energy resides in the potential of a hidden axion field that is generated by a new QCD-like force that gets strong at the scale lambda approximately = nu2/M approximately = rho(DE)(1/4). The evolution rate is given by a second seesaw that leads to the axion mass m(phi) approximately = lambda2/f, with f approximately = M.