Phenomenology of a Pseudo-Scalar Inflaton: Naturally Large Nongaussianity

Many controlled realizations of chaotic inflation employ pseudo-scalar axions. Pseudo-scalars \phi are naturally coupled to gauge fields through c \phi F \tilde{F}. In the presence of this coupling, gauge field quanta are copiously produced by the rolling inflaton. The produced gauge quanta, in turn, source inflaton fluctuations via inverse decay. These new cosmological perturbations add incoherently with the "vacuum" perturbations, and are highly nongaussian. This provides a natural mechanism to generate large nongaussianity in single or multi field slow-roll inflation. The resulting phenomenological signatures are highly distinctive: large nongaussianity of (nearly) equilateral shape, in addition to detectably large values of both the scalar spectral tilt and tensor-to-scalar ratio (both being typical of large field inflation). The WMAP bound on nongaussianity implies that the coupling, c, of the pseudo-scalar inflaton to any gauge field must be smaller than about 10^{2} M_p^{-1}.Comment: 45 pages, 7 figure

Comportamento de monta e características seminais de suínos jovens landrace e large white Mating behavior and seminal characteristics in young landrace and large white boars

O objetivo deste trabalho foi avaliar o comportamento de monta e as características seminais de machos Landrace (LD) e Large White (LW) dos 143 aos 232 dias de idade. A partir dos 143 dias de idade, 62 machos suínos foram avaliados quanto ao comportamento de monta. A partir dos 150 dias de idade, o sêmen foi coletado de 33 desses machos durante onze semanas para avaliar a produção e qualidade espermáticas. Não houve diferenças entre as raças em relação ao comportamento de monta (p=0,105). Durante o período de coletas de sêmen, houve aumento do volume de sêmen, da concentração espermática, do número de espermatozóides (SPTZ) ejaculados e da liberação diária de SPTZ (LDE). O percentual de células espermáticas anormais diminuiu durante o período e não houve diferença entre as raças (P=0,523). Os machos LD ejacularam maior volume de sêmen (P=0,016), de espermatozóides totais por ejaculado (P=0,070) e apresentaram maior LDE (P=0,042). Esses dados indicam que machos LD apresentam maior produção espermática e maior potencial para produzir doses de sêmen no período pós-púbere.<br>The aim of this work was to evaluate mating behavior and seminal characteristics of Landrace (LD) and Large White (LW) boars from 143 to 232 days of age. With 143 days of age, LD (n=28) and LW (n=34) boars were evaluated in relation to mating behavior. Being 150 days of age, semen was collected from 33 of these males during eleven weeks to evaluate sperm production and quality. No difference was observed between breeds in relation to mating behavior. During the period of semen collection, there was an increase in semen volume, sperm concentration and motility, total sperm in ejaculate, and in daily sperm output (DSO). The percent of abnormal sperm cells decreased during the period and there was no difference between breeds (P=0.523). The LD boars ejaculated higher semen volume (P=0,016), total sperm in ejaculate (P=0.070), and showed higher DSO (P=0.042). These data indicate that LD boars show higher sperm production, and higher potential to produce semen doses in post pubertal period