Curvature Inspired Cosmological Scenario

Using modified gravity with non-linear terms of curvature, $R^2$ and $R^{(r +2)}$ (with $r$ being the positive real number and $R$ being the scalar curvature), cosmological scenario,beginning at the Planck scale, is obtained. Here, a unified picture of cosmology is obtained from $f(R)-$ gravity. In this scenario, universe begins with power-law inflation, followed by deceleration and acceleration in the late universe as well as possible collapse of the universe in future. It is different from $f(R)-$ dark energy models with non-linear curvature terms assumed as dark energy. Here, dark energy terms are induced by linear as well as non-linear terms of curvature in Friedmann equation being derived from modified gravity.It is also interesting to see that, in this model, dark radiation and dark matter terms emerge spontaneously from the gravitational sector. It is found that dark energy, obtained here, behaves as quintessence in the early universe and phantom in the late universe. Moreover, analogous to brane-tension in brane-gravity inspired Friedmann equation, a tension term $\lambda$ arises here being called as cosmic tension. It is found that, in the late universe, Friedmann equation (obtained here) contains a term $- \rho^2/2\lambda$ ($\rho$ being the phantom energy density) analogous to a similar term in Friedmann equation with loop quantum effects, if $\lambda > 0$ and brane-gravity correction when $\lambda < 0.$Comment: 19 Pages. To appear in Int. J. Thro. Phy

A brief social-belonging intervention in the workplace: evidence from a field experiment

Brief interventions that strengthen an individual’s sense of social belonging have been shown to improve outcomes for members of underrepresented, marginalized groups in educational settings. This paper reports insights based on an attempt to apply this type of intervention in the technology sector. Adapting a social-belonging intervention from educational psychology, we implemented a quasi-random field experiment, spanning twelve months, with 506 newly hired engineers (24% female) in the R&D function of a west coast technology firm. We did not find a statistically significant effect of the treatment on a core attainment outcome—bonus relative to base salary—that exhibited a significant gender gap, with women receiving proportionally lower bonuses than men. We did not find anticipated gender gaps in promotion rates or social network centrality, and we also did not find a statistically significant effect of the treatment for women on these outcomes. Drawing on meaningful differences between educational versus workplace settings, we identify four theoretical moderators that might influence the efficacy of social-belonging interventions adapted from educational settings into the workplace. Finally, based on the limitations of our study design, we provide four recommendations that future researchers might adopt.Accepted manuscrip

AR(1) sequence with random coefficients: Regenerative properties and its application

Let $\{X_n\}_{n\ge0}$ be a sequence of real valued random variables such that $X_n=\rho_n X_{n-1}+\epsilon_n,~n=1,2,\ldots$, where $\{(\rho_n,\epsilon_n)\}_{n\ge1}$ are i.i.d. and independent of initial value (possibly random) $X_0$. In this paper it is shown that, under some natural conditions on the distribution of $(\rho_1,\epsilon_1)$, the sequence $\{X_n\}_{n\ge0}$ is regenerative in the sense that it could be broken up into i.i.d. components. Further, when $\rho_1$ and $\epsilon_1$ are independent, we construct a non-parametric strongly consistent estimator of the characteristic functions of $\rho_1$ and $\epsilon_1$