On sign-changeable interaction in FLRW cosmology

Distance-Redshift in Inhomogeneous FLRW

We give distance–redshift relations in terms of elliptic integrals for three different mass distributions of the Friedmann-Lemâitre-Robertson-Walker (FLRW) cosmology. These models are dynamically pressure free FLRW on large scales but, due to mass inhomogeneities, differ in their optical properties. They are the filled-beam model (standard FLRW), the empty-beam model (no mass density exists in ...

analyzing patterns of classroom interaction in efl classrooms in iran

با به کار گیری روش گفتما ن شنا سی در تحقیق حا ضر گفتا ر میا ن آموزگا را ن و زبا ن آموزا ن در کلا سهای زبا ن انگلیسی در ایرا ن مورد بررسی قرار گرفت. ا هداف تحقیق عبا رت بودند از: الف) شنا سا ئی سا ختارهای ارتبا ط گفتا ری میا ن معلمین و زبا ن آموزا ن ب) بررسی تا ثیر نقش جنسیت دبیرا ن و زبا ن آموزان بر سا ختا رهای ارتبا ط گفتا ری میا ن آنها پ) مشخص کردن اینکه آ یا آموزگاران غا لب بر این ارتبا ط گف...

Deviation of geodesics in FLRW spacetime geometries

The geodesic deviation equation (‘GDE’) provides an elegant tool to investigate the timelike, null and spacelike structure of spacetime geometries. Here we employ the GDE to review these structures within the Friedmann–Lemâıtre–Robertson–Walker (‘FLRW’) models, where we assume the sources to be given by a non-interacting mixture of incoherent matter and radiation, and we also take a non-zero co...

Dependence of Halo Properties on Interaction History, Environment and Cosmology

I present results from numerical N-body simulations regarding the effect of merging events on the angular momentum distribution of galactic halos as well as a comparison of halo growth in semi-analytic vs. N-body methods. A total of six simulations are used spanning 3 cosmologies: a standard flat Ω0 = 1 model, an open Ω0 = 0.3 model and a “tilted” flat Ω0 = 1 model with spectral index n = 0.8. ...

Path planning in changeable environments