A late time accelerated FRW model with scalar and vector fields via Noether symmetry

We study the evolution of a three-dimensional minisuperspace cosmological model by the Noether symmetry approach. The phase space variables turn out to correspond to the scale factor of a flat Friedmann-Robertson-Walker (FRW) model, a scalar field with potential function $V(\phi)$ with which the gravity part of the action is minimally coupled and a vector field of its kinetic energy is coupled with the scalar field by a coupling function $f(\phi)$. Then, the Noether symmetry of such a cosmological model is investigated by utilizing the behavior of the corresponding Lagrangian under the infinitesimal generator of the desired symmetry. We explicitly calculate the form of the coupling function between the scalar and the vector fields and also the scalar field potential function for which such symmetry exists. Finally, by means of the corresponding Noether current, we integrate the equations of motion and obtain exact solutions for the scale factor, scalar and vector fields. It is shown that the resulting cosmology is an accelerated expansion universe for which its expansion is due to the presence of the vector field in the early times, while the scalar field is responsible of its late time expansion.Comment: 9 pages, 2 figures, typos corrected, Refs. adde

From strings in 6d to strings in 5d

We show how recent progress in computing elliptic genera of strings in six dimensions can be used to obtain expressions for elliptic genera of strings in five-dimensional field theories which have a six-dimensional parent. We further connect our results to recent mathematical results about sheaf counting on ruled surfaces.Comment: 17 pages, 4 figures. v3: Definitions clarified, Section "Concluding Thoughts" adde

The role of multiple intelligences (MI) in listening proficiency

Not many studies have so far quantitatively investigated the role of Multiple Intelligences (MI) in language teaching and almost no research has explored the role of MI in listening proficiency. In this study, the role of MI was investigated by giving one hundred and fifty-one junior and senior English language students an actual TOEFL listening comprehension test and a Multiple Intelligences Development Assessment Scales (MIDAS) questionnaire. The results suggest that, although all the intelligences positively correlate with performance on TOEFL listening comprehension, only linguistic intelligence has a statistically significant but low correlation with TOEFL listening. Furthermore, the results of regression analysis indicate that linguistic intelligence is included as a predictor of listening proficiency while other intelligences are excluded. The results provide quantitative data that, except for linguistic intelligence that has a small role, other intelligences do not make any contribution to performance in listening proficiency and learners with different intelligences have equal chances and only those with low linguistic intelligence need more help