Licia Verde

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Dark energy
Licia Verde
University of Pennsylvania
www.physics.upenn.edu/lverde
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We (and all of chemistry) are a small minority in
the Universe.
We do not know what 96 of the Universe is !
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1992
(Bennett et al. 1996)
2003
(Bennett et al. 2003)
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What is this map telling us about the Universe
composition? and HOW?
Were seeing sound!
From W. Hu web page
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1 deg
compression
Acoustic peaks
(extrema)
rarefaction
compression
Primordial ripples
Fundamental mode
(from Hinshaw et al. 2003)
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compression
Rarefaction etc
Potential wells
baryons
Geometry
Primordial ripples
Fundamental mode
(from Hinshaw et al. 2003)
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Method
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Vacuum energy
L
(also known as dark energy or cosmological
constant)
vacuum
1917
L
V1
E1 rv V1
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Vacuum energy
L
(also known as dark energy or cosmological
constant)
vacuum
1917
L
Negative pressure!
V1
V2
E1 rv V1
E2 rv V2
E2gtE1
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Makes the Universe expand
but
It happens to become visible just now
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z0.3 age11 billion years
z0
14 billion years
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How?
Tools statistics.
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Additional indications Supernovae
Standard candles
Function of geometry and Content of Universe
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Science for real
Vacuum Energy density
Supernovae
Dark energy
CMB
Matter content
Galaxy survey
Universe is FLAT
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the dark side of the Universe
We have indications that
More than 90 of the mass in the Universe is
DARK
About 85 of mass in the Universe is made of
matter unknown to earth
We have some candidates
and experiments for direct dark matter searches
Progress might come soon
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the dark side of the Universe
We have indications that
More than 90 of the mass in the Universe is
DARK
About 80 of whats in the Universe is not even
matter, its dark energy
what it is?
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Much ado about nothing
We havent got a clue
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Much ado about nothing
We havent got a clue
Remember negative pressure
w-1
Cosmological constant
Something else QUINTESSENCE.
L
Then not constant in time nor in space.
Evolving
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Quintessence
(Spergel et al 2003)
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Where do we go from here?
Devise observations to learn more about dark
energy.
w(t), w(z)
use galaxy clusters
use spectra of galaxies
use cross correlations
Etc. etc.
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Something really funny
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Nothing really funny
?
Thanks to the WMAP science team and the 2dFGRS
team
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Nothing really funny
?