Exam and consultation

[Larisa_MEPhI]

Are there any explanations for the fact that there are no stable nuclei with A=5 in the early Universe?

[Maxim Khlopov]

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

[Ilya Rozhnov]

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?

[Maxim Khlopov]

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

[Ilya Rozhnov]

По поводу экзамена: если вам удобно, то я бы назначил на 12 завтра.

[Maxim Khlopov]

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

[Ilya Rozhnov]

Хорошо, я постараюсь прийти пораньше.

[Maxim Khlopov]

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