Dark Matter and Dark Energy Eiichiro Komatsu (MPI f. Astrophysik) - - PowerPoint PPT Presentation

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Dark Matter and Dark Energy Eiichiro Komatsu (MPI f. Astrophysik) - - PowerPoint PPT Presentation

Aug 21, 2022 294 likes •603 views

Dark Matter and Dark Energy Eiichiro Komatsu (MPI f. Astrophysik) Max Planck Forum, Botschaft von Japan April 19, 2018 Best Evidence The best evidence (though not the first evidence) for both dark matter and dark energy came from

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Dark Matter and Dark Energy

Eiichiro Komatsu (MPI f. Astrophysik) Max Planck Forum, Botschaft von Japan April 19, 2018

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Best Evidence

  • The best evidence (though not the first evidence)

for both dark matter and dark energy came from measurements of the Cosmic Microwave Background (kosmische Mikrowellenhintergrundstrahlung)

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Fireball Universe

Hot and Dense

Time Space

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Hot and Dense Hot

Expansion Fireball Universe

Time Space

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Hot Cooled down Hot and Dense

Expansion Expansion Fireball Universe

Time Space

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Definitive Result

  • Those photons which filled the fireball Universe are

still with us

  • There are 410 such photons per cubic centimetre
  • Due to the expansion of space and cooling down,

these photons are cold, and their wavelength is in the radio/microwave region

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上坂浩光監督の全天ドーム映画

「HORIZON~宇宙の果てにあるもの」

多摩六都科学館（東京）上映中 仙台市天文台（宮城）上映中 他、各地で上映予定 Full-dome movie by Director Hiromitsu Kohsaka

“HORIZON” Beyond the Edge of the Visible Universe

Trailer available on YouTube Nominated for one of 12 movies, which will be shown at the upcoming “FullDome Festival” at Jena, May 23–26, 2018

http://fulldome-festival.de

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All you need to do is to detect radio

  • waves. For example, 1% of noise on

the TV is from the fireball Universe

  • Dr. Hiranya Peiris

（University College London）

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Sky in the visible light [~500nm]

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Sky in the microwaves [~1mm]

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Sky in the microwaves [~1mm]

Light from the fireball Universe filling our sky The Cosmic Microwave Background (CMB)

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The sky in various wavelengths

Visible -> Near Infrared -> Far Infrared -> Submillimeter -> Microwave

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WMAP Science Team

July 19, 2002

  • WMAP was launched on June 30, 2001
  • The WMAP mission ended after 9 years of operation
  • Prof. Wilkinson
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Outstanding Questions

  • Where does anisotropy in CMB temperature come

from?

  • This is the origin of galaxies, stars, planets, and

everything else we see around us, including

  • urselves
  • The leading idea: quantum fluctuations in

vacuum, stretched to cosmological length scales by a rapid exponential expansion of the universe called “cosmic inflation” in the very early universe

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Data Analysis

  • Decompose temperature

fluctuations in the sky into a set of waves with various wavelengths

  • Make a diagram showing the

strength of each wavelength

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Long Wavelength Short Wavelength 180 degrees/(angle in the sky)

Amplitude of Waves [μK2]

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Kosmische Miso Suppe

  • When matter and radiation were hotter than 3000 K,

matter was completely ionised. The Universe was filled with plasma, which behaves just like a soup

  • Think about a Miso soup (if you know what it is).

Imagine throwing Tofus into a Miso soup, while changing the density of Miso

  • And imagine watching how ripples are created and

propagate throughout the soup

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  • WMAP determined the

abundance of various components in the Universe

  • As a result, we came to

realise that we do not understand 95%

  • f our Universe…

H&He Dunkle Materie Dunkle Energie

Cosmic Pie Chart

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Matter and Expansion

  • How would space expand in an empty Universe?

–A: Continue to expand with a constant velocity (i.e., no acceleration or deceleration)

  • How would space expand in a matter-dominated Unvierse?

–A: Gravity pulls space and expansion decelerates

  • Too much matter means a re-collapse of the Universe!

Big Bang Big Crunch

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Accelerating Universe

  • However, the observations tell us that expansion is speeding up!
  • This cannot be due to matter

–Something that is not even matter: Dark Energy Big Bang

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No Dark Energy on Earth

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What if Dark Energy dominates?

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Dark Energy determines the future of the Universe

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Future of the Universe

  • It all depends on what Dark Energy will do!
  • We are “safe” in Earth because there is a lot more

matter than Dark Energy on Earth today

  • If Dark Energy stays the same or decreases in the future,

we will be safe forever

  • If Dark Energy increases over time, it will eventually

exceed the matter density, and everything will be ripped

  • apart. A catastrophic ending called “Big Rip”
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Big Rip