Jonathan White
3rd year PhD student, Cosmology group, YITP

Life before Japan
Brought up in the Lake District, England
Undergraduate studies at theUniversity of Oxford
A year of work in a start-up company(working with my old professor)
Masters course at Imperial College London

Life before Japan
Brought up in the Lake District, England
Undergraduate studies at theUniversity of Oxford
A year of work in a start-up company(working with my old professor)
Masters course at Imperial College London

Life before Japan
Brought up in the Lake District, England
Undergraduate studies at theUniversity of Oxford
A year of work in a start-up company(working with my old professor)
Masters course at Imperial College London

Life before Japan
Brought up in the Lake District, England
Undergraduate studies at theUniversity of Oxford
A year of work in a start-up company(working with my old professor)
Masters course at Imperial College London

Why Japan?
Developed a personal interest in Japan after making friends withinternational students from Japan at university
Was also aware that the research community is very much aninternational one. Advances in both experimental and theoreticalphysics require the collaboration of experts all over the world, e.g.
Kamiokande and K2K here in Japan
Professor Sasaki (my supervisor) is one of the pioneers of cosmologicalperturbation theory, and has strong ties with UK research groups

Why Japan?
Developed a personal interest in Japan after making friends withinternational students from Japan at university
Was also aware that the research community is very much aninternational one. Advances in both experimental and theoreticalphysics require the collaboration of experts all over the world, e.g.
Kamiokande and K2K here in Japan
Professor Sasaki (my supervisor) is one of the pioneers of cosmologicalperturbation theory, and has strong ties with UK research groups

Why Japan?
Developed a personal interest in Japan after making friends withinternational students from Japan at university
Was also aware that the research community is very much aninternational one. Advances in both experimental and theoretical physics
require the collaboration of experts all over the world, e.g.
Kamiokande and K2K here in Japan
Professor Sasaki (my supervisor) is one of the pioneers of cosmologicalperturbation theory, and has strong ties with UK research groupsMy research - Inflation

My research - Inflation
T~1027K

My research - Inflation
T~1027K

Opaque(Compton scattering)

Universe expands
and coolsMy research - Inflation
T~1027K

T~3000K

Opaque(Compton scattering)

Universe expands
and coolsMy research - Inflation
T~1027K

T~3000K

Opaque(Compton scattering)

Universe expands
and cools

Transparent
Photons produced after
inflation travel freely!

My research - Inflation
T~1027K

T~3K

T~3000K

Opaque(Compton scattering)

Universe expands
and cools

Transparent
Photons produced after
inflation travel freely!

My research - Inflation
If we look to the sky, wecan see the radiation thathas been travelling towards
us since the epoch ofrecombination - the CMB(cosmic microwavebackground)

COBE 1992

WMAP 2003

PLANCK 2003

My research - Inflation
If we look to the sky, we
can see the radiation thathas been travelling towards
us since the epoch ofrecombination - the CMB(cosmic microwave
background)T⇠ 10 5
TCOBE 1992

WMAP 2003

PLANCK 2003

My research - Inflation
If we look to the sky, we
can see the radiation thathas been travelling towards
us since the epoch ofrecombination - the CMB(cosmic microwavebackground)

COBE 1992WMAP 2003

PLANCK 2003

Fluctuations due to quantum
fluctuations in inflation.
T⇠ 10 5TMy research - Inflation
If we look to the sky, wecan see the radiation thathas been travelling towards
us since the epoch ofrecombination - the CMB(cosmic microwave
background)

COBE 1992

WMAP 2003

PLANCK 2003

Fluctuations due to quantum
fluctuations in inflation.
T⇠ 10 5T

Can use these fluctuations toprobe inflationary physics,
which is at E ~ 1013 Gev!

My research - Inflation
If we look to the sky, wecan see the radiation thathas been travelling towards
us since the epoch ofrecombination - the CMB(cosmic microwavebackground)

COBE 1992

WMAP 2003

PLANCK 2003

Fluctuations due to quantum
fluctuations in inflation.
T⇠ 10 5T

Can use these fluctuations toprobe inflationary physics,
which is at E ~ 1013 Gev!
“The Universe is the poor
man’s particle accelerator”

Studying JapaneseAfter arriving in Japan in October 2010 I took a 5-month language course.
My level is still very basic, but it has allowed me toStudying JapaneseAfter arriving in Japan in October 2010 I took a 5-month language course.
My level is still very basic, but it has allowed me to
Cope with daily life outside of university, such as renting anapartment, getting around on public transport etc

Studying JapaneseAfter arriving in Japan in October 2010 I took a 5-month language course.
My level is still very basic, but it has allowed me to
Cope with daily life outside of university, such as renting anapartment, getting around on public transport etc
Make friends outside of university, where not everyone speaks
EnglishStudying JapaneseAfter arriving in Japan in October 2010 I took a 5-month language course.
My level is still very basic, but it has allowed me toCope with daily life outside of university, such as renting anapartment, getting around on public transport etc
Make friends outside of university, where not everyone speaks
EnglishFeel more a part of my research group, being able to socialise
outside office hours

Studying English
Being able to speak English opens up so many opportunities, both
personal and academic.

Studying English
Being able to speak English opens up so many opportunities, both
personal and academic.
Advice from my experience of learning Japanese:Don’t hesitate to try and speak. People always seem happy
when I try, even if what I say is far from perfect, and I think welearn from our mistakes.

Studying English
Being able to speak English opens up so many opportunities, both
personal and academic.
Advice from my experience of learning Japanese:Don’t hesitate to try and speak. People always seem happy
when I try, even if what I say is far from perfect, and I think welearn from our mistakes.
Take any opportunity to use English. It’s easy at a university
like Kyoto - clubs, circles, international students etcStudying English
Being able to speak English opens up so many opportunities, both
personal and academic.
Advice from my experience of learning Japanese:Don’t hesitate to try and speak. People always seem happy
when I try, even if what I say is far from perfect, and I think welearn from our mistakes.
Take any opportunity to use English. It’s easy at a university
like Kyoto - clubs, circles, international students etc
It’s not just about study.
Enjoy making international
friends, watching movies
etc. Learning a new
language then follows
naturally.

Thank youPlease feel free to contact me at any time with any questions, or just to chat!
jwhite@yukawa.kyoto-u.ac.jp

My research - Inflation
In the Big Bang model of the universe, the universe at earlier times ismuch hotter and electrons are not bound to nuclei. We therefore havevery frequent Compton scattering of photons off electrons.

My research - Inflation
In the Big Bang model of the universe, the universe at earlier times ismuch hotter and electrons are not bound to nuclei. We therefore havevery frequent Compton scattering of photons off electrons.
At some point, the universe cools to the extent that electrons becomebound to protons, meaning that the scattering of photons becomes very
rare. This epoch of “recombination’’ defines the surface of lastscattering, after which photons travel freely

My research - Inflation
In the Big Bang model of the universe, the universe at earlier times ismuch hotter and electrons are not bound to nuclei. We therefore havevery frequent Compton scattering of photons off electrons.
At some point, the universe cools to the extent that electrons becomebound to protons, meaning that the scattering of photons becomes very
rare. This epoch of “recombination’’ defines the surface of lastscattering, after which photons travel freely
If we look to the sky, we can see these photons that have been travelling
towards us since the epoch of “recombination’’ - the CMBMy research - Inflation
In the Big Bang model of the universe, the universe at earlier times ismuch hotter and electrons are not bound to nuclei. We therefore havevery frequent Compton scattering of photons off electrons.
At some point, the universe cools to the extent that electrons becomebound to protons, meaning that the scattering of photons becomes very
rare. This epoch of “recombination’’ defines the surface of lastscattering, after which photons travel freely
If we look to the sky, we can see these photons that have been travelling
towards us since the epoch of “recombination’’ - the CMB
Nasa’s COBE satellite
determined a very uniform
temperature distribution acrossthe sky! T = 2.728 K

My research - Inflation
But the maximum distance that light could have travelled up to the time of“recombination’’ is relatively small, so we don’t expect causally disconnected
regions of the universe to have been at the same temperature.

My research - Inflation
But the maximum distance that light could have travelled up to the time of“recombination’’ is relatively small, so we don’t expect causally disconnected
regions of the universe to have been at the same temperature.

Inflation helps to solve this problem - if the universe undergoes
accelerated expansion before recombination, then causally connected
regions can be expanded to sizes larger than the observable universeMy research - Inflation
But the maximum distance that light could have travelled up to the time of“recombination’’ is relatively small, so we don’t expect causally disconnected
regions of the universe to have been at the same temperature.

Inflation helps to solve this problem - if the universe undergoes
accelerated expansion before recombination, then causally connected
regions can be expanded to sizes larger than the observable universe
What is the physics driving
inflation? Looking a bit
closer, there are temperaturefluctuations ~ 10 −5. We try
to constrain a variety ofinflationary models bycomparing the fluctuations
they predict with thoseobserved