Dark Energy Part 2: LCDM Cosmology

[RUTA]

This is Part 2 of a 3-part series explaining evidence for so-called “dark energy” leading to a current positive cosmological acceleration. The evidence comes from fitting the SCP Union2.1 type Ia supernova data which indicates the existence of a cosmological constant $\Lambda$ (read “Lambda”, thus $\Lambda$CDM is sometimes written LCDM) in Einstein’s equations (EEs) of general relativity (GR). This $\Lambda$ is referred to as “dark energy” and creates a current positive cosmological acceleration, as we will see below. This is in stark contrast to what we found in Part 1 for Einstein-deSitter (EdS) cosmology (a spatially flat, dust-filled cosmology model). There I showed that the cosmological acceleration in EdS cosmology is always negative. I will use some of the results from Part 1 here to obtain EdS plus $\Lambda$, aka $\Lambda$CDM, where “CDM” stands for “cold dark...

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