Gauge fields in a string-cigar braneworld

In this work we investigate the properties of an Abelian gauge vector field in a thin and in a smoothed string-like braneworld, the so-called string-cigar model. This thick brane scenario satisfies the regularity conditions and it can be regarded as an interior and exterior string-like solution. The source undergoes a geometric Ricci flow which is connected to a variation of the bulk cosmological constant. The Ricci flow changes the width and amplitude of the massless mode at the brane core and recover the usual thin string-like behavior at large distances. By numerical means we obtain the Kaluza-Klein (KK) spectrum for both the thin brane and the string-cigar. It turns out that both models exhibit a mass gap between the massless and the massive modes and between the high and the low mass regimes. The KK modes are smooth near the brane and their amplitude are enhanced by the string-cigar core. The analogue Schr\"odinger potential is also tuned by the geometric flow.Comment: The discussion about the Kaluza-Klein spectrum of the gauge field was improved. Numerical analysis was adapted to the conventional notation on Kaluza-Klein number. Some graphics were modified for considering other notation. Results unchanged. References added. Corrected typos. 17 pages. 6 figures. To match version to appears in Physics Letters

Identification of seminal parameters predictive of conception rates in Angus and Nelore bulls used in TAI.

The ability to predict male fertility is highly desirable for bulls used in AI. Timed artificial insemination (TAI) represents a breakthrough in the use of AI in Brazil and other countries. Numerous causes contribute to the wide range of results and/or unsatisfactory pregnancy rates in TAI programs, highlighting the factors inherent in the bovine female in addition to several factors inherent to quality of semen used. Regarding the quality of semen used in AI programs, differences reported in fertility could be attributed to variation in sperm qualitative characteristics. Consequently, the success of bovine AI programs largely depends on the use of good quality semen. When only high fertility bulls are used, better conception rates are achieved, reducing costs of reproductive programs. Thus, some authors have shown that semen used in TAI has great impact on pregnancy rates, and various biomarkers of sperm quality are required to predict the fertility of bull spermatozoa (Oliveira et al., 2013, Holden et al., 2017). Our goal is to correlate different methods of post-thaw semen evaluation with the P/AI of Nelore (zebu) cows subjected to TAI to identify the candidate predictors of conception rate.Proceedings of the international Bull Fertility Conference, 2018, Westport

Emergence of fractal cosmic space from fractional quantum gravity

Based on Padmanabhan's theory, the spatial expansion of the Universe can be explained by the emergence of space as cosmic time progresses. To further explore this idea, we have developed fractional-fractal Friedmann and Raychaudhuri equations for an isotropic and homogeneous universe. Our analysis has also delved into how Padmanabhan's concept fits into the framework of fractional quantum gravity. Our research shows that a fractal horizon model strongly supports the validity of the emerging Universe paradigm and its connection to horizon thermodynamics. This study indicates early how the emergent gravity perspective might manifest in quantum gravity. By utilizing the fractional-fractal Friedmann and Raychaudhuri equations, we have established that the mainstream cosmology model can be justified without a dark matter component. As a result, the standard $\Lambda$CDM model has been reduced to $\Lambda$-Cold Baryonic Matter, which has significant implications for our understanding of the Universe.Comment: 20 pages, 1 figure, to appear in Eur. Phys. J. Plu

Qualidade do solo em diferentes usos da terra em Ouro/SC.

O objetivo deste trabalho foi avaliar a qualidade do solo em diferentes sistemas de uso da terra através de variáveis biológicas na microbacia hidrográfica do Rio Doze Passos no município de Ouro-SC