Download Realized in String Theory - Department of Physics & Astronomy

String Cosmology
of 11-Dimensional
Spacetime
Dr. Gerald B. Cleaver
EUCOS-CASPER
Baylor University
CASPER
www.baylor.edu/~CASPER
A10a     a  g abc b Ac .
10
500
Science Fiction has become Science
Extra Dimensions (7 to be exact)
 Parallel Universes (at least 1 + maybe a few more)
 Multiple Universes (perhaps ~ 1010^100)
 Warped Spacetime
 Time before Time
 End of the Universe Predicted

 Anti-Gravity is pulling apart our universe
~ in Trillion yrs even atoms torn apart
A10a     a  g abc b Ac .
10
500
Realized in String Theory (M-Theory)
500 Physicists seeking Einstein’s final goal
the Theory of Everything (Physical)
A10a     a  g abc b Ac .
10
500
String Theory implies
nature of reality & existence is
more complex …
more beautiful …
yet more simple …
then ever imagined before!
500
1010
Outline
Brief Intro to Strings/M-Theory
 String Cosmology
 Destiny of the Stringy Universe &
Landscape of String Theory

Aa     a  g abc b Ac .
Visible Universe
13.7 billion
light years
In diameter
= 8 x1022 mi
trillion galaxies,
trillion stars per
galaxy
All Matter & Forces in the Universe
Unified by String Theory
Particles & Forces
Like Notes on a Violin String
A
B
♪♫
♪♫
C

D
♪♫
♪♫
E
♪♫
F
G
♪♫
Interactions of Lines
(w/ infinites, anomalies,
nonsense probabilities)

Interactions of Surfaces
(w/ sensible probabilities)
String Interactions consistent w/
Relativity
Quantum Mechanics
Requires String Theory w/
9 + 1 Dimensional Spacetime
Astronomy, OFotU
Strings have two vibrations – CW & CCW
Spin = # of Vibrations in our 3+1 Dim. Spacetime
Gravitons = Spin 2 Particles
= Strings w/ both vibes in 3+1 Dim S-T
Photons, Gluons, W+,-, Z (non-grav. force part.)
= Spin 1 Particles
= Strings w/ 1 vibe in 3+1 Dim S-T
& 1 vibe in 6 Dim Comp Space
SUSYMatter
= Spin 0 Particles
= Strings w/ both vibes in 6 Dim Comp
Space
Circular
Too Simple
Spherical
Toroidal
too simple …
to generate exact “vibration” modes needed
for strong & weak nuclear force particles
(Gluons & W+,-, Z),
to generate exact vibration modes needed for
all matter particles (three generations of
quarks, electrons, neutrinos, along with
Higgs)
So more complex shapes investigated …
Require
Calabi-Yau Compactification for all
6 Compactified Dimensions
2 Dim Surface C-Y Surface—Need to extend to 6 Dim
Energy Modes
String Duality
Only 3 Directions Inflated-Why?
Finite Initial Size and
Temperature of Universe
String Explanation for Only
3 Large Dimensions!
P-dimensional Object
Interactions
Nagging Problem for 1st Decade (1985-95):
Not Just 1 10-Dimensional String Theory
But 5!
Solution: Duality (Equality) of All 5
String Theories
Each ‘Theory” is SAME THEORY
IN DIFFERENT
MATHEMATICAL LANGUAGE
O
Й
‫א‬
‫ڜ‬
Membrane
String

w/ 10 Dim

w/ 11 Dim
Two 9-brane “Universes”= “Us & Them”
and extra dimension between
Compactify 6 of the 9 Spatial
Directions of each Brane as Before
Effective 5-Dimensional Theory
Size of 5th Dimension?
10-33 cm < y < 0.1 mm
Tests for sub-mm.directions
Fgrav = -Gm1m2/r2  -Gm1m2/r2+n
1/r2 form of gravity being tested.
Verified down to 0.15 mm at Univ. of Wash.
with 97% confidence level
Manufacturing of
Stringy Blackholes!



If sub-mm. dimension then it may be possible to
produce mini-black holes (with peco-second halflives) at Fermilab & CERN this decade!
NO THREAT TO THE EARTH (NOR EVEN
CHICAGO OR GENEVA)!!!
Mini-black holes have distinct decays—easily
identifiable!
Detectors for black holes under construction
for Fermilab and CERN
Proposed Explanation for Big Bang
Implying Time Before Time!
Astronomy, OFotU
The colliding Branes would not remain perfectly
flat as they approach each other due to quantum
effects.
Big Bang Inflations occurs in bumps on Branes
that collide first.
Multiple, separated, Big Bang regions might have
been formed from distinct collision points of
Branes!
 Multiple universes on our Brane besides 1+
Parallel Branes along an extra spatial direction
M-Theory &
Our Standard 3 Large Dimensions
Cosmic Microwave Background (CMB)
history
CMB
CMB Temp =
2.73 Degrees
above absolute
Zero
Temp variations
of 1 part in 100,000
denoted by color
variations
Blue is hottest,
Red is coldest
Recent Observation of Earliest Galaxies—Formed 1 billion years after Big Bang
OBSERVATION: Eight distant infant galaxies -- essentially giant globs
of hydrogen with a few hot young stars -- lie inside a thin filament,
visualized with a computer overlay. The hot stars make the hydrogen
glow. Other objects in the image are nearer galaxies or stars.
New Scientist, 5 Feb 2005
String Landscape
~ 10100 Models (with Fluxes) in M-Theory
String/M-Theory as presently understood has a large parameter space of variables
(angles between each compactified direction, lengths of each, plus things called
fluxes and torques) each leading to universes (observable, hidden, or both) with
differing properties. On the order of > 10100 different universes all seem equally
possible. Why our particular String/M-Theory universe?
Some scientists (e.g. Stephen Hawking) are suspicious that determination of a
particular choice of ALL of the M-Theory parameters might not be totally
determinable, based on Gödel’s Theorem, which says that one cannot formulate a
finite system of axioms to prove every result in mathematics. This means that
inconsistencies or indeterminacies can arise if one tries to prove statements that
refer to themselves.
A physical theory is a mathematical model. So if there are mathematical results
that cannot be proved, there are physical problems that cannot be solved. We do
not live outside of the universe, but instead we and our theories are both part of
the universe we are describing. Hence our theories are also self-referring. And thus
we might suspect that any Theory of Everything determined by a finite number of
known parameters or variables might ultimately be incomplete or undetermined!
String/M-Theory




Provides unified explanation of all 4 forces &
matter particles.
Develops deeper understanding of nature of
spacetime and gravity.
Presents our universe with a simplicity, order and
beauty never before imagined. Simultaneously
provides for complexity of universe.
Suggests more to our universe than ever of
dreamed prior.
Astronomy, OFotU
 String/M-Theory as likely
GOD’S BLUEPRINT FOR THE UNIVERSE!
CASPER
Center for Astrophysics, Space Physics &
Engineering Research
www.baylor.edu/~CASPER
Interesting String (Cosmology) Web Sites (also image sources):
http://www.superstringtheory.com/ John Schwarz’ "The Official String Theory Web Site"
http://www.sukidog.com/jpierre/strings/ String Tutorial with glossary, refs & links
http://www.superstring-theory.com/EnglishVersion.html another excellent intro
http://www.superstringtheory.com/cosmo/index.html
http://www.ba.infn.it/~gasperin/
http://feynman.princeton.edu/~steinh/ Great string cosmology sites
http://www.nuclecu.unam.mx/%7Ealberto/physics/string.html
http://dmoz.org/Science/Physics/Quantum_Mechanics/
http://pages.wooster.edu/bboroson/clinks.html
worthwhile collections of links to other major string sites