Section 238
They are very beautiful, and when I look at their names, Chunhua and Qiushi, well, this couple is really destined to be together.
Of course, he would not improve his impression of Chen Chunhua because of this incident. Chen Chunhua is indeed very good, but Xiao Yi still does not consider recruiting students in nuclear physics.
Finally, in desperation, Xiao Yi accelerated the interview process. Only when he met a student who liked his direction, he would communicate with the other party a little more.
In this way, after a few days, all the interviews and exchanges were over. Although he was exhausted, he finally selected the most satisfactory student.
In mathematics, there were Liang Qiushi and Chen Muhua, and in physics, only one person was planned to be recruited, named Sun Yuan.
Sun Yuan has excellent ability in theoretical physics. During his undergraduate studies, he had published a first-tier paper on quantum chromodynamics.
It can be said that Sun Yuan is also the only student among so many recommended students who can independently complete a first-tier paper.
According to Sun Yuan, this paper took him two full years to complete, and it was not published until August this year.
Although it is not a top journal, it is quite difficult for a student like him to achieve such results.
Especially this is a paper on theoretical physics.
The threshold of theoretical physics is also quite high, not much worse than pure mathematics, otherwise physics and mathematics would not despise each other.
In the end, Xiao Yi reported the names of the three people to the college, and the list will be made public after the college has counted them.
However, what happened after that has nothing to do with Xiao Yi at all.
"Finally, I can continue to study my own things."
After working for four days at the University of Science and Technology, Xiao Yi returned to his Science Island Laboratory on the fifth day.
The circle of land around the laboratory can now be seen to be surrounded by the construction site fence again.
The second phase expansion project of the Science Island Laboratory has officially begun.
Although the second phase project is quite large, there are more people working, so it is still expected to complete the expansion in one year.
The main contractor is still the Huajian Group Engineering Bureau that has cooperated before, and even the project manager is Manager Wang who met at the beginning.
After standing in front of the window and taking a look at the construction situation, Xiao Yi sat back at his desk and took out the draft paper he had used to study the NS equation.
"Now, I have tried to study from several generalized initial condition spaces, but no matter how much I calculated, or how I deformed these spaces according to the explosion tendency theory, I could never get close to the effect I wanted."
"Hmm..."
He narrowed his eyes slightly.
"First, this new space needs to meet the following conditions: it can control the regularity of the solution, it can control the growth of nonlinear terms, and it can handle more generalized initial conditions."
After thinking for a while, he began to try.
"Let's start with the basic definitions of Sobolev space and Besov space..."
[Hs(Rn)={f∈L2(Rn):(1+∣ξ∣2)s/2f^(ξ)∈L2(Rn)}, where f^ is the Fourier transform of f. 】
【Bp, qs(Rn)={f∈S′(Rn):∥f∥Bp, qs<∞}, where ∥f∥Bp, qs is defined by wavelet transform or decomposition coefficients. 】
"Now introduce a new function space X^s, whose definition should combine the characteristics of Sobolev space and Besov space, and introduce additional conditions to control the growth of nonlinear terms..."
"Let Xs(Rn) be the set of functions f that satisfy the following conditions..."
[Sobolev type regularity: ∥f∥Hs=(∫Rn(1+∣ξ∣2)s∣f^(ξ)∣2dξ)1/2<∞……]
[Besov type localization characteristics: ∥f∥Bp, qs=(j=0∑∞……]
Time passed, and in the initial attempt, Xiao Yi successfully created a new function space that combined the characteristics of two different function spaces.
"In this new space X^s, we can do some analysis..."
Xiao Yi made some comments on the draft paper next to him. Line summary.
[Representation of initial conditions: Check whether the initial conditions belong to X^s and calculate their norm. ]
[Regularity estimation: Use the regularity conditions in X^s to prove the regularity of the solution. ]
[Control of nonlinear terms: Through the nonlinear control conditions in X^s, ensure that the nonlinear terms will not cause the solution to blow up. ]
"Well..."
Xiao Yi frowned slightly, and finally shook his head: "Not enough."
This new function space can only be said to be a little useful, but not completely useful.
However, despite this...
Xiao Yi quickly showed a relaxed smile.
Because he knew that he had found the key to success.
All the puzzles are missing the most critical method.
And the proof of the NS equation is already within reach!
Chapter 212 He always creates miracles
Time is passing slowly.
A new function space, and a function space that can combine three characteristics, is certainly not so easy to get.
Although the role played by the bursting trend theory is very critical, it cannot solve all the problems, especially the regularity problem.
The regularity problem refers to the study of the smoothness and continuity of the solution of the partial differential equation.
The core of this problem is to determine and describe whether the solution of the equation has good differential properties under certain conditions, that is, whether it is smooth, continuous or has a certain order of derivatives.
It is also an important issue to understand the behavior and properties of the solution of the equation.
How to ensure that it also has a good estimate of the regularity problem in this new function space still needs to be carefully considered.
However, for Xiao Yi, these problems are certainly difficult, but since he has found a focus, the rest is just equivalent to solving a relatively difficult math problem.
Solving problems is not that difficult for him.
…
Two weeks have passed in the blink of an eye.
Let’s not talk about Xiao Yi’s progress, the exchange activities between recommended graduate students and tutors held by the School of Mathematics and the School of Physics have also ended.
The tutors and recommended students who saw each other directly filled in the information afterwards.
Students who have not yet chosen a mentor can only find a mentor they like better and communicate with them through emails.
Anyway, no matter where they are, mentors still prefer these recommended students, so these recommended students don’t have to worry about not having a mentor.
However, for the vast majority of recommended students who participated in this exchange activity, they still care more about who won the "first prize".
"First prize" naturally refers to becoming Xiao Yi's student. More than a hundred people have signed up for exchanges with Xiao Yi. Obviously, they all know that not everyone can get Xiao Yi's favor. In the end, only a few students will have the opportunity to stand out from these more than a hundred students.
It's just like taking the civil service exam.
So isn't this the first prize?
In the end, after the list was announced, the students who were not selected were regretful, but they didn't forget to look at the students who were selected by Xiao Yi.
Good guy, why are they all from Qinghua University?
Forget about the fact that Sun Yuan from the School of Physics is from Peking University. After all, Peking University's physics does not have much advantage over HKUST. At most, it is just an academic advantage. However, considering that physics is basically a pure scientific research field, the academic advantage does not really play a big role, so it is understandable that Sun Yuan went to HKUST.
But these two guys in mathematics, are you so awesome, are you coming to HKUST to bully others?
Simply Baidu the names of Chen Muhua and Liang Qiushi, and you can easily find the various achievements these two people made during their undergraduate studies. One is better than the other, and they are all awesome people who can be reported.
Titles like this: [Student tyrant story: He won national awards for three consecutive years, GPA 3.88, and has published three papers independently...]
Or: [He is from Qinghua, GPA 3.95 for three years, and won multiple mathematics competition awards...]
There is no comparison.
Faced with these two awesome people, no matter how helpless others are, they can only choose to give up struggling in the end.
Competing with these two is completely overestimating one's own ability.
In addition, the announcement of this list not only attracted a lot of attention and reactions among students, but also caused various reactions among the teachers of the School of Mathematics.
After all, Xiao Yi was equivalent to taking away the two best students of the School of Mathematics this year.
They almost bit their back teeth.
But there was no way, who let him be the winner of the Fields Medal?
He was naturally attractive to those outstanding students.
So they could only comfort themselves. Although Xiao Yi took away the two best students, the third, fourth, fifth... these outstanding students were still left for them, and everyone could still share.
As for the School of Physics, there was not much reaction to Xiao Yi taking Sun Yuan away.
After all, there are many directions in physics. Sun Yuan is indeed excellent for being able to independently complete a first-tier paper during his undergraduate studies, but among students studying other fields, there are still top students whose past performance is not worse than Sun Yuan.
Moreover, since Sun Yuan is engaged in pure theoretical physics such as quantum mechanics, Xiao Yi is the most suitable person to be his mentor.
Among the other mentors in the School of Physics, there are really few people who specialize in these things, and most of them are still engaged in applied physics and the like.
After the list is finalized, we will wait for them to enter the school in September next year, which is more than eight months away.
In addition, this year's postgraduate examination also started at the end of December. The college, which has just finished the exchange activities between recommended students and mentors, has shifted its focus to this examination.
Although the students who pass these admission examinations may not be as good as those recommended students, it is inevitable that there will be some dark horses among them, so we still have to pay attention to them.