Exam and consultation

Moderators: Maxim Khlopov, Konstantin Belotsky

Re: Exam and consultation

New postby Larisa_MEPhI on Mon 10 Jan 2011 19:49

Are there any explanations for the fact that there are no stable nuclei with A=5 in the early Universe?
It doesn't matter what you write, it matters who is your advisor!
User avatar
Larisa_MEPhI
 
Posts: 24
Joined: Mon 27 Sep 2010 20:29
Location: Russia, Moscow


Re: Exam and consultation

New postby Maxim Khlopov on Mon 10 Jan 2011 19:58

It reflects experimental fact of nuclear physics: there is no stable nucleus with A=5.
Therefore there is a gap that strongly suppresses formation of nuclei with A>5 in Big Bang Nuceleosynthesis.
Regards
M.Yu.Khlopov
[i]Хлопов Максим Юрьевич
Maxim Khlopov[/i]
User avatar
Maxim Khlopov
Administrateur du site
 
Posts: 1682
Joined: Sat 9 Aug 2008 19:42
Location: Paris


Re: Exam and consultation

New postby Ilya Rozhnov on Mon 10 Jan 2011 21:22

Бариогенезис выходит за рамки стандартной модели, я правильно понимаю?
Можно вернуть равновесие частиц и античастиц, произведя над материей какие-то обратные действия? Можно ли это сделать (и вообще говорить об этом) локально? Если равновесие удастся вернуть, то после этого оно нарушится в ту же сторону (частиц), или не обязательно?
User avatar
Ilya Rozhnov
 
Posts: 24
Joined: Mon 27 Sep 2010 17:02


Re: Exam and consultation

New postby Maxim Khlopov on Mon 10 Jan 2011 22:12

Dear Ilya,
Yes, baryosynthesis needs physics beyond the Standard model.
In particular, you need processes with baryon and lepton charge nonconservation.
Therefore you need local restoration of these kind of processes.
In very hot stars electron-positron plasma may be in equilibrium, but it is not sufficient to restore equilibrium for processes with lepton charge violation.
In principle, if the equilibrium is restored, all the excess of particles over antiparticles is washed out, but the successive behaviour and generation of excess is determined by the mechanism of baryosynthesis and may lead to different result.
Regards
M.Yu.Khlopov
[i]Хлопов Максим Юрьевич
Maxim Khlopov[/i]
User avatar
Maxim Khlopov
Administrateur du site
 
Posts: 1682
Joined: Sat 9 Aug 2008 19:42
Location: Paris


Re: Exam and consultation

New postby Ilya Rozhnov on Tue 3 May 2011 14:54

По поводу экзамена: если вам удобно, то я бы назначил на 12 завтра.
User avatar
Ilya Rozhnov
 
Posts: 24
Joined: Mon 27 Sep 2010 17:02


Re: Exam and consultation

New postby Maxim Khlopov on Tue 3 May 2011 17:45

Dear Ilya,
For me it would be fine 12.00 Moscow time tomorrow.
I'd like to recommend you to come earlier, take the ticket and prepare to be ready to answer that time.
We'll need some time for you to put the main points of your answer on the whiteboard
See you tomorrow
Regards
M.Yu.Khlopov
[i]Хлопов Максим Юрьевич
Maxim Khlopov[/i]
User avatar
Maxim Khlopov
Administrateur du site
 
Posts: 1682
Joined: Sat 9 Aug 2008 19:42
Location: Paris


Re: Exam and consultation

New postby Ilya Rozhnov on Tue 3 May 2011 18:07

Хорошо, я постараюсь прийти пораньше.
User avatar
Ilya Rozhnov
 
Posts: 24
Joined: Mon 27 Sep 2010 17:02


Re: Exam and consultation

New postby Maxim Khlopov on Tue 3 May 2011 18:13

After consultation with K.M.Belotsky we decided that it would be better if you come to him at 12 and be ready to answer at 13.00.
Belotsky will confirm you.
Regards
M.Yu.Khlopov
[i]Хлопов Максим Юрьевич
Maxim Khlopov[/i]
User avatar
Maxim Khlopov
Administrateur du site
 
Posts: 1682
Joined: Sat 9 Aug 2008 19:42
Location: Paris


Previous

Return to КУРС ПО КОСМОМИКРОФИЗИКЕ 2010/2011

Who is online

Users browsing this forum: No registered users and 2 guests

cron