Quantum Theory and The Universe

Microworld ⇔ Macroworld

Monday, May 19, 14

This talk will revolve around one big idea:

The structure of the Universe, on large scales, arises from quantum fluctuations.

Monday, May 19, 14

To do justice to that idea, I will

explain what quantum fluctuations are

explain how structure in the universe arises from “cosmic seeds”

explain how inflation turns quantum fluctuations into cosmic seeds

discuss the evidence

discuss what it all means

Monday, May 19, 14

Quantum Fluctuations

Monday, May 19, 14

What our senses perceive as empty space is, within our best equations, revealed to be full of spontaneous activity.

Monday, May 19, 14

Monday, May 19, 14

Fluctuating fields as virtual particles

Monday, May 19, 14

The original Feynman diagram

Monday, May 19, 14

Genesis 1: Structure from Seeds

Monday, May 19, 14

Development of gravitational instability

Monday, May 19, 14

Genesis 2: Seeds from Quantum Fluctuations

Monday, May 19, 14

Monday, May 19, 14

Putting It All Together

Monday, May 19, 14

Monday, May 19, 14

Evidence

Monday, May 19, 14

Evidence for quantum fluctuations:

Casimir effect

Basically everything in high energy physics, including, for example, Higgs particle production!

Monday, May 19, 14

Monday, May 19, 14

decay

production

tt + ?X?

tt + W+W- + ?Y?

Monday, May 19, 14

Evidence for growth of seeds:

We see the seeds, directly, imprinted in the cosmic microwave background

We can calculate the resulting distribution of matter, and compare to observations.

Monday, May 19, 14

Monday, May 19, 14

Monday, May 19, 14

Evidence for inflation:

The seeds, in detail, look like blown-up quantum fluctuations

Monday, May 19, 14

Monday, May 19, 14

Evidence for inflation:

Recently, “B modes” - special patterns of polarization in the cosmic microwave background - have been observed.

Monday, May 19, 14

Monday, May 19, 14

A candidate explanation is that these B-mode patterns were imprinted by fluctuations in the geometry of space and time itself:

Waves of (quantum) gravity

Monday, May 19, 14

(no Earth required!)

Monday, May 19, 14

This exciting, amazing possibility can and will be tested decisively, in coming months, through further observations.

Monday, May 19, 14

Implications

Monday, May 19, 14

The most profound implications:

The universe is governed by mathematical laws, that humans can find and understand.

The laws operate in the same way for all times, and at all places.

Straightforward extrapolation of the laws, as discovered in lab experiments, to much more extreme conditions seems to work well.

Monday, May 19, 14

More detailed implications of B modes:

gravity waves exist

gravity must be quantized

(??) possibly coming soon:

a grand synthesis of the separate forces

the why of inflation

Monday, May 19, 14

↑inverse coupling

strength

electric

weak

strong

large energy, short distance→

Why I ♥ SUSY

Gravity fits too!(roughly)

Monday, May 19, 14

Susy?♪♪Forces Unify ♪♪

♪♪MH ≈125 GeV♪♪

Monday, May 19, 14

EUnification

⇡ 2⇥ 1016 GeV

EInflation

?⇡ 2⇥ 1016 GeV

Coincidence? - Maybe not!

Monday, May 19, 14

And finally, two metaphorical “implications”:

Microcosm and macrocosm are one.

The Universe observes itself.

Monday, May 19, 14

Monday, May 19, 14

Monday, May 19, 14

Monday, May 19, 14

Monday, May 19, 14

three fundamental “forces”

six fundamental “materials”

(plus gravity)

(plus 2 repeats) (plus Higgs particle)

Monday, May 19, 14

03/01/2003 Frank Wilczek, MIT

SO(10)One “force”One “material”

Monday, May 19, 14