The Small Observed Baryon Asymmetry from a Large Lepton Asymmetry

Primordial Big-Bang Nucleosynthesis (BBN) tightly constrains the existence of any additional relativistic degrees of freedom at that epoch. However a large asymmetry in electron neutrino number shifts the chemical equilibrium between the neutron and proton at neutron freeze-out and allows such additional particle species. Moreover, the BBN itself may also prefer such an asymmetry to reconcile predicted element abundances and observations. However, such a large asymmetry appears to be in conflict with the observed small baryon asymmetry if they are in sphaleron mediated equilibrium. In this paper we point out the surprising fact that in the Standard Model, if the asymmetries in the electron number and the muon number are equal (and opposite) and of the size required to reconcile BBN theory with observations, a baryon asymmetry of the Universe of the correct magnitude and sign is automatically generated within a factor of two. This small remaining discrepancy is naturally remedied in the supersymmetric Standard Model.Comment: 14 page

Field Quantization in 5D Space-Time with Z2_2-parity and Position/Momentum Propagator

Field quantization in 5D flat and warped space-times with Z$_2$-parity is comparatively examined. We carefully and closely derive 5D position/momentum(P/M) propagators. Their characteristic behaviours depend on the 4D (real world) momentum in relation to the boundary parameter ($l$) and the bulk curvature (\om). They also depend on whether the 4D momentum is space-like or time-like. Their behaviours are graphically presented and the Z$_2$ symmetry, the "brane" formation and the singularities are examined. It is shown that the use of absolute functions is important for properly treating the singular behaviour. The extra coordinate appears as a {\it directed} one like the temperature. The $\delta(0)$ problem, which is an important consistency check of the bulk-boundary system, is solved {\it without} the use of KK-expansion. The relation between P/M propagator (a closed expression which takes into account {\it all} KK-modes) and the KK-expansion-series propagator is clarified. In this process of comparison, two views on the extra space naturally come up: orbifold picture and interval (boundary) picture. Sturm-Liouville expansion (a generalized Fourier expansion) is essential there. Both 5D flat and warped quantum systems are formulated by the Dirac's bra and ket vector formalism, which shows the warped model can be regarded as a {\it deformation} of the flat one with the {\it deformation parameter} \om. We examine the meaning of the position-dependent cut-off proposed by Randall-Schwartz.Comment: 44 figures, 22(fig.)+41 pages, to be published in Phys.Rev.D, Fig.4 is improve

How can we test seesaw experimentally?

The seesaw mechanism for the small neutrino mass has been a popular paradigm, yet it has been believed that there is no way to test it experimentally. We present a conceivable outcome from future experiments that would convince us of the seesaw mechanism. It would involve a variety of data from LHC, ILC, cosmology, underground, and low-energy flavor violation experiments to establish the case.Comment: 5 pages, 4 figure

Gaugino Mass without Singlets

In models with dynamical supersymmetry breaking in the hidden sector, the gaugino masses in the observable sector have been believed to be extremely suppressed (below 1 keV), unless there is a gauge singlet in the hidden sector with specific couplings to the observable sector gauge multiplets. We point out that there is a pure supergravity contribution to gaugino masses at the quantum level arising from the superconformal anomaly. Our results are valid to all orders in perturbation theory and are related to the `exact' beta functions for soft terms. There is also an anomaly contribution to the A terms proportional to the beta function of the corresponding Yukawa coupling. The gaugino masses are proportional to the corresponding gauge beta functions, and so do not satisfy the usual GUT relations.Comment: 25 pages, references added, typos and grammar correcte

Low-frequency local field potentials and spikes in primary visual cortex convey independent visual information

Local field potentials (LFPs) reflect subthreshold integrative processes that complement spike train measures. However, little is yet known about the differences between how LFPs and spikes encode rich naturalistic sensory stimuli. We addressed this question by recording LFPs and spikes from the primary visual cortex of anesthetized macaques while presenting a color movie.Wethen determined how the power of LFPs and spikes at different frequencies represents the visual features in the movie.Wefound that the most informative LFP frequency ranges were 1– 8 and 60 –100 Hz. LFPs in the range of 12– 40 Hz carried little information about the stimulus, and may primarily reflect neuromodulatory inputs. Spike power was informative only at frequencies <12 Hz. We further quantified “signal correlations” (correlations in the trial-averaged power response to different stimuli) and “noise correlations” (trial-by-trial correlations in the fluctuations around the average) of LFPs and spikes recorded from the same electrode. We found positive signal correlation between high-gamma LFPs (60 –100 Hz) and spikes, as well as strong positive signal correlation within high-gamma LFPs, suggesting that high-gamma LFPs and spikes are generated within the same network. LFPs<24 Hz shared strong positive noise correlations, indicating that they are influenced by a common source, such as a diffuse neuromodulatory input. LFPs<40 Hz showed very little signal and noise correlations with LFPs>40Hzand with spikes, suggesting that low-frequency LFPs reflect neural processes that in natural conditions are fully decoupled from those giving rise to spikes and to high-gamma LFPs

Supersymmetric Singlet Majorons and Cosmology

We examine cosmological constraints on the lepton number breaking scale in supersymmetric singlet majoron models. Special attention is drawn to the model dependence arising from the particular choice of a certain majoron extension and a cosmological scenario. We find that the bounds on the symmetry breaking scale can vary substantially. Large values of this scale can be allowed if the decoupling temperature of smajoron and majorino exceeds the reheating temperature of inflation. In the opposite case an upper bound depending on the majoron model can be obtained which, however, is unlikely to be much larger than $10^{10}$ GeV.Comment: 14 pages, 2 figures, IC/94/40, SNUTP 94-15, TUM - TH - 164/9

Quark mass uncertainties revive KSVZ axion dark matter

The Kaplan-Manohar ambiguity in light quark masses allows for a larger uncertainty in the ratio of up to down quark masses than naive estimates from the chiral Lagrangian would indicate. We show that it allows for a relaxation of experimental bounds on the QCD axion, specifically KSVZ axions in the $2-3 \mu$eV mass range composing 100% of the galactic dark matter halo can evade the experimental limits placed by the ADMX collaboration.Comment: 9 pages, 5 figure

Cosmological Higgs fields

We present a time-dependent solution to the coupled Einstein-Higgs equations for general Higgs-type potentials in the context of flat FRW cosmological models. Possible implications are discussed.Comment: 5 pages, no figures. Version to be published in Phys. Rev. Lett. Changes: references and citations added; introduction partly modified; expanded discussion of relations between parameters in the Higgs potentia