Cosmology and cosmological constant: New progress

宇宙項と宇宙論：最近の進展と展望
Cosmological constant and cosmology:
New progress and future perspective
~ Einstein and cosmological constant ~
白水徹也（東京工業大学大学院理工学研究科基礎物理学専攻）
Tetsuya Shiromizu (Tokyo Institute of Technology)
Einstein and C.C.
1917
C.C. was introduced to make universe static
1917 deSitter solution (C.C.)
1922 Friedmann solution (no C.C.)
1927 Lemaitre (Friedmann + C.C. )
1929 Hubble law
3 C.C.
“C.C.” at present
“C.C.” at the beginning
Volvo 3cc
“C.C.” in extra dimension
C.C. at present
C.C. ~ Dark energy




Why so small?
Why exists?
Why couples to gravity?
Why now?
(Yokoyama-san, Doi-san, Linde-san)
“C.C.” in the early universe
Inflation
WMAP data
(Yokoyama-san, Linde-san)
“C.C.” in extra dimension

Negative “C.C.” is preferred in
superstring theory

Negative “C.C.” and brane bring us
new direction
✓a kind of inflation in direction to extra dim. : warped extra dim.
✓String landscape
(Sasaki-san, Linde-san)
Current purpose
Look at new progress and idea in theory and
observations
Figure out future perspective in 21st century
Programme
Chair T. Tanaka(Kyoto U.) 座長田中貴浩氏
J.Yokoyama (RESCEU, U.Tokyo) 横山順一氏
“Both the beginning and end are Inflation” (Overview)
M.Doi (IoA, U.Tokyo)
土居守氏
“Supernove and C.C.”
-- Break -Chair N.Ohta(Osaka U.) 座長太田信義氏
M.Sasaki (Yukawa, Kyoto U. ) 佐々木節氏
“Warped extra dimension and C.C.”
A.Linde (Stanford/Yukawa)
“Inflation, dark energy and string theory”
Cosmology with C.C.

Homogeneous and isotropic universe
Degree of freedom: scale factor ~ radius of universe ( a(t) )
From Einstein equation
V(a)
curvature
a 2  V (a)  K
K<0
K>0
(i) Λ=0
4G   m0  r 0  2  2
V (a)  
 3  4 a  a
3  a
a 
6
K<0
K>0
Einstein’s static universe
(ii) Λ> 0
“C.C.” in extra dimension
From ten/eleven to lower dim.
Stabilisation of extra dim. due to flux (of branes)
Lower dimensional point of view
Log( radius )
Flux
Curvature of extra dim.
Negative C.C. (Anti-deSitter space times)
Programme
Chair T. Tanaka(Kyoto U.) 座長田中貴浩氏
J.Yokoyama (RESCEU, U.Tokyo) 横山順一氏
“Both the beginning and end are Inflation” (Overview)
M.Doi (IoA, U.Tokyo) 土居守氏
“Supernove and C.C.”
-- Break -Chair N.Ohta(Osaka U.) 座長太田信義氏
M.Sasaki (Yukawa, Kyoto U. ) 佐々木節氏
“Warped extra dimension and C.C.”
A.Linde (Stanford/Yukawa)
“Inflation, dark energy and string theory”

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