From New to Large Field Inflation: Comparison with WMAP3

We briefly summarize and update a class of inflationary models from the early eighties based on a quartic (Coleman-Weinberg) potential for a gauge singlet scalar (inflaton) field. For vacuum energy scales comparable to the grand unification scale, the scalar spectral index n_s=0.94-0.97, in very good agreement with the WMAP three year results. The tensor to scalar ratio r<~0.14 while alpha=dn_s/d ln k=~-10^-3. For vacuum energy scales >~10^16 GeV, the inflationary scenario switches from `new' to `large-field' (V\propto\phi^2) inflation. An SO(10) version naturally explains the observed baryon asymmetry via non-thermal leptogenesis.Comment: 7 pages, 4 figures, 1 table. Based on a talk given by Q. Shafi at the 2nd International Conference on The Dark Side of the Universe (DSU 2006), Madrid (Spain), 20-24 June 200

Observable Gravity Waves From Supersymmetric Hybrid Inflation

We identify models of supersymmetric hybrid inflation in which the tensor-to-scalar ratio, a canonical measure of gravity waves produced during inflation, can be as large as 0.03 or so, which will be tested by the Planck satellite experiment. The scalar spectral index lies within the WMAP one sigma bounds, while $|d n_s / d\ln k| \lesssim 0.01$.Comment: (v1) 19 pages, 1 table, 3 figures. (v2) 20 pages; updated figures, included additional discussion, footnotes, and referenc

Delivering bad news to followers: leaders' cognitive reappraisal vs. suppression requests on followers' emotion regulation and leader-follower relations

We investigated the effects of leaders’ emotional regulation request (suppression or cognitive reappraisal) on follower’s felt and expressed anger and attitudes, as well as the effect of follower’s expressed anger on leaders’ attitudes toward followers. Study 1 using a 2x3 experimental design, examined the role of a hypothetical female/male leader’s suppression/cognitive-reappraisal request following the delivery of bad news on followers’ (229 undergraduates) felt/expressed anger and attitudes toward the leader. Results indicated that leader’s reappraisal request was more successful in decreasing felt anger compared to a control condition as well as decreasing expressed anger compared to both suppression request and control condition. Female leaders who requested suppression were evaluated less favorably than male leaders when followers held stereotypical attitudes towards female leadership. Study 2 showed that leaders’ (n = 32 executives) are more likely to perceive the expressed anger of followers’ and develop negative attitudes towards them following a suppression versus a reappraisal request. We found that regardless of followers’ gender, leaders’ attitudes were more positive when perceived follower anger was low

The Polonyi Problem and Upper bound on Inflation Scale in Supergravity

We reconsider the Polonyi problem in gravity-mediation models for supersymmetry (SUSY) breaking. It has been argued that there is no problem in the dynamical SUSY breaking scenarios, since the Polonyi field acquires a sufficiently large mass of the order of the dynamical SUSY-breaking scale Lamada_{SUSY}. However, we find that a linear term of the Polonyi field in the Kahler potential brings us back to the Polonyi problem, unless the inflation scale is sufficiently low, H_{inf} < 10^{8} GeV, or the reheating temperature is extremely low, T_{R} < 100 GeV. Here, this Polonyi problem is more serious than the original one, since the Polonyi field mainly decays into a pair of gravitinos.Comment: 17 pages, 1 figure, minor corrections, published versio

Non-Minimal B-L Inflation with Observable Gravity Waves

We consider non-minimal \lambda \phi^4 inflation in a gauged non-supersymmetric U(1)_{B-L} model containing the gravitational coupling \xi \mathcal{R} \Phi^\dagger \Phi, where \mathcal{R} denotes the Ricci scalar and the standard model singlet inflaton field \Phi spontaneously breaks the U(1)_{B-L} symmetry. Including radiative corrections, the predictions 0.956 < n_s < 0.984 and 0.007 < r < 0.1 for the scalar spectral index and tensor to scalar ratio r lie within the current WMAP 1-\sigma bounds. If the B-L symmetry breaking scale is of order a TeV or so, one of the three right handed neutrinos is a plausible cold dark matter candidate. Bounds on the dimensionless parameters \lambda, \xi and the gauge coupling g_{B-L} are obtained.Comment: 7 pages, 9 figures, minor corrections, final version published in Physics Letters

SO(10)-GUT Coherent Baryogenesis

A model for GUT baryogenesis, coherent baryogenesis within the framework of supersymmetric SO(10), is considered. In particular, we discuss the Barr-Raby model, where at the end of hybrid infl ation charge asymmetries can be created through the time-dependent higgsino-gaugino mixing mass matrix. These asymmetries are processed to Standard Model matter through decays via nonrenormalizable (B-L)-violating operators. We find that a baryon asymmetry in accordance with observation can be generated. An appendix is devoted to provide useful formulas and concrete examples for calculations within SO(10).Comment: 30 pages, 3 figure

Anarchy and Leptogenesis

We study if leptogenesis works successfully together with the neutrino mass anarchy hypothesis. We find that the predicted neutrino mass spectrum is sensitive to the reheating temperature or the inflaton mass, while the distributions of the neutrino mixing angles and CP violation phases remain intact as determined by the invariant Haar measure of U(3). In the case of thermal leptogenesis, the light neutrino mass distribution agrees well with the observations if the reheating temperature is O(10^{9-11}) GeV. The mass spectrum of the right-handed neutrinos and the neutrino Yukawa matrix exhibit a certain pattern, as a result of the competition between random matrices with elements of order unity and the wash-out effect. Non-thermal leptogenesis is consistent with observation only if the inflaton mass is larger than or comparable to the typical right-handed neutrino mass scale. Cosmological implications are discussed in connection with the 125GeV Higgs boson mass.Comment: 29 pages, 6 figures. v2: figures and references added. v3: published in JHE