Lambda-CDM model

Okay.

So the standard cosmological model, often called Lambda-CDM, assumes dark energy is a cosmological constant.

It predicts that the density of dark energy remains perfectly flat, unchanging over time.

It pushes with the exact same strength, no matter how large the universe gets.

Well, so the focal question is gonna be: which model best explains the total evidence? Uh, and how do we rank them in terms of their explanatory adequacy? And to keep everybody honest, we need a, a yardstick to measure things against.

And so the standard Big Bang model, the Lambda-CDM, the cosmological constant, cold dark matter, uh, standard model of cosmology is, is gonna be our yardstick in that respect.

So what does the standard model of cosmology do? Well, on the basis of basically six numbers or so, uh, so, uh, how much ordinary matter is there? How much dark matter is there? Uh, what's the strength of the primordial ripples that seeded galaxies? So there's a slight unevenness in the total energy density of the primordial, uh, fireball, if you will.

Uh, which by Einstein's equations is the same thing as the unevenness in the curvature of space.

... all of these things kind of dovetail in a way that a philosopher of science from the 19th century, William Whewell, called consilience.

Independent standards of, of evidence from disconnected directions coming together to yield a cohesive picture.

So there's a beauty about the standard model of cosmology, uh, the Lambda-CDM model, and there's a reason we take it as a kind of the baseline for cosmological explanation.

But there are some things that it, um, doesn't explain.

The empty space itself is a cosmic laboratory.

Supervoids like Boötes provide critical, irreplaceable testing grounds for our standard cosmological parameters, specifically the Lambda-CDM model.

Lambda-CDM.

Hmm.

Okay.

For our listeners who might not have a whiteboard of physics equations in their living room, let's break that down.

Lambda-CDM is essentially the standard model of Big Bang cosmology, right?

Yes.