Modification of Heisenberg uncertainty relations in non-commutative Snyder space-time geometry

We show that the Euclidean Snyder non-commutative space implies infinitely many different physical predictions. The distinct frameworks are specified by generalized uncertainty relations underlying deformed Heisenberg algebras. Considering the one-dimensional case in the minisuperspace arena, the bouncing Universe dynamics of loop quantum cosmology can be recovered.Comment: 5 pages; title changed, to appear in PR

Matter instability in modified gravity

The Dolgov-Kawasaki instability discovered in the matter sector of the modified gravity scenario incorporating a 1/R correction to Einstein gravity is studied in general f(R) theories. A stability condition is found in the metric version of these theories to help ruling out models that are unviable from the theoretical point of view.Comment: 4 pages, revtex, to appear in Phys. Rev. D. In the revised version, an error concerning the Palatini version of these theories has been corrected and the references update

Cigarrinha-das-Pastagens : uma praga que retorna com as chuvas.

bitstream/item/139024/1/cnpgc-divulga-08.pdfCNPGC. Serie nao convencional

Haematobia irritans L: um novo problema para a bovinocultura no Brasil.

bitstream/item/138551/1/COT-25.pdfCNPGC