Positive Ricci curvature through Cheeger deformation

Let $(M,g)$ be a Riemannian manifold with an isometric $G$-action. If a principal orbit has finite fundamental group and $\mathrm{Ric}_{M^{reg}/G}\geq 1$, Searle--Wilhelm proved that $M$ admits a new metric $\tilde g$ of positive Ricci curvature. $\tilde g$ is obtained after a conformal change followed by a Cheeger deformation. The question remained on whether it is sufficient to consider only the Cheeger deformation to attain positive Ricci curvature on the new metric $\tilde g$. Here we approach this question by giving necessary and sufficient conditions on the $G$-action. In particular, we construct an infinite family of manifolds satisfying the hypothesis of Searle--Wilhelm that do not develop positive Ricci curvature after Cheeger deformation. Further exploring the theory, we give a alternative proofs for Lawson--Yau result on positive scalar curvature under non-abelian symmetry, among others.Comment: 26 pages. Exposition reviewed. Applications include

On the finiteness of the noncommutative supersymmetric Maxwell-Chern-Simons theory

Within the superfield approach, we prove the absence of UV/IR mixing in the three-dimensional noncommutative supersymmetric Maxwell-Chern-Simons theory at any loop order and demonstrate its finiteness in one, three and higher loop orders.Comment: 9 pages, 2 figures, revtex

Diagnóstico da agricultura familiar no município de Moju, Pará.

bitstream/item/63291/1/Oriental-Doc104.pd

Mass-degenerate Higgs bosons at 125 GeV in the Two-Higgs-Doublet Model

The analysis of the Higgs boson data by the ATLAS and CMS Collaborations appears to exhibit an excess of h --> gamma\gamma events above the Standard Model (SM) expectations; whereas no significant excess is observed in h --> ZZ* --> {four lepton} events, albeit with large statistical uncertainty due to the small data sample. These results (assuming they persist with further data) could be explained by a pair of nearly mass-degenerate scalars, one of which is a SM-like Higgs boson and the other is a scalar with suppressed couplings to W+W- and ZZ. In the two Higgs doublet model, the observed \gamma\gamma and ZZ* --> {four lepton} data can be reproduced by an approximately degenerate CP-even (h) and CP-odd (A) Higgs boson for values of \sin(\beta-\alpha) near unity and 0.7 < \tan\beta < 1. An enhanced \gamma\gamma signal can also arise in cases where m_h ~ m_H, m_H ~ m_A, or m_h ~ m_H ~ m_A. Since the ZZ* --> {four lepton} signal derives primarily from a SM-like Higgs boson whereas the \gamma\gamma signal receives contributions from two (or more) nearly mass-degenerate states, one would expect a slightly different invariant mass peak in the ZZ* --> {four lepton} and \gamma\gamma channels. The phenomenological consequences of such models can be tested with additional Higgs data that will be collected at the LHC in the near future.Comment: 18 pages, 19 pdf figures, v2: references added, v3&v4: added refs and explanation

Dissimilaridade entre acessos de jaqueira (Artocarpus heterophyllus Lam.) com base em características de fruto.

Anais do 1º Simpósio da Rede de Recursos Genéticos Vegetais do Nordeste (I RGVNE), Cruz das Almas, nov. 2013