Zhang Zhongyuan wanted to ignore this hand, but he saw that many classmates simply ignored the three minutes he gave them, and instead looked back at Chen Zhou first.

There's no way around it, you can't let people do it, right?

So, in the expectant eyes of his classmates, Zhang Zhongyuan named him: "Chen Zhou, you can answer." ”

Chen Zhou smiled and stood up.

"Think of the Klein quaternion group as a form of quaternial permutation, s4 is a 24th-order group, and Klein is a 4th-order group. ”

Thus, from the Lagrangian theorem, we know that the quotient group s4/Klein is a group of order 6. There are only two types of 6th-order groups in the sense of isomorphism, one is the 6th-order cyclic group and the other is S3. ”

"This lists all the elements in s4/Klein, or can be written in the form of a left companion. If we look at the representative elements of those co-sets, we can see that s4/Klein obviously cannot form a 6th-order cyclic group, so s4/Klein must be isomorphic to s3. ”

At this point, the answer to this question is also out. ”

Chen Zhou's tone was steady, and he completely explained the proof ideas and methods of this question.

Zhang Zhongyuan looked at Chen Zhou and stopped talking.

And some of the students below have already begun to check the calculations, and some are looking at Chen Zhou with adoring eyes.

The big guy is the big guy, as soon as this question comes out, the answer will come out, without thinking.

It's just that many of the students who checked the calculation found that Chen Zhou ignored a problem.

That is one less step to prove that the Klein quaternion is a regular subgroup.

They began to prove the content of this part.

Zhang Zhongyuan looked at the speed at which the students could write, which was much faster than the speed of writing in his usual class, and couldn't help but sigh lightly in his heart.

Looking at Zhang Zhongyuan, who had not spoken, Chen Zhou thought about it, should his thinking be right?

But immediately, he realized that he had said a little less, so he added, "By the way, the proof that the Klein quaternion here is a regular subgroup is too simple, so I didn't say it." ”

Hearing Chen Zhou's voice, the classmates who were trying to prove that the Klein quaternary group was a regular subgroup, the hand holding the pen couldn't help but be stunned, and then stopped.

Their faces were full of wry smiles.

Zhang Zhongyuan, who saw this scene, finally couldn't help but say: "Okay, you sit down first, let's take a look at this question ......"

In the second half of the class, Zhang Zhongyuan looked at the time from time to time, and he felt that this was the most "difficult" class since he taught.

It's not that there is any special reason, it's just that he is too familiar with Chen Zhou, this kid hasn't come to class for so long, and he suddenly came to class, which makes him a little ...... Adapt......

"Okay, that's all for today's lesson, go back and remember to do the exercises. ”

With Zhang Zhongyuan's words, this "Abstract Algebra" class is over.

Chen Zhou was not in a hurry to leave, he noticed that Zhang Zhongyuan had been watching him.

If he understands correctly, it should mean, don't leave after class.

Seeing that Chen Zhou didn't leave, the students in the classroom also slowed down.

Chen Zhou returned from MIT, and they had only seen him on news broadcasts and online.

This will be a real person, but you have to take a good look at it and take a breath of the school bully.

If you can't keep it, you can't fail the final exam not far away?

Even if you take a picture!

They still have a deep memory of the general failure of the high generation.

But obviously, Zhang Zhongyuan is not happy, he still has something to do with Chen Zhou, what are you doing nonsense?

"Why? Don't you want to get out of class? Why don't we come back ......?"

When Zhang Zhongyuan said this, he unconsciously paused, and when he saw the excited students, he suddenly changed his words: "Why don't we assign more after-class exercises, and everyone will do them here?"

Hearing this, some students hurriedly said, "Don't, Professor Zhang, don't you pack up your things?

Then, Zhang Zhongyuan saw a strange scene.

These students, one by one, did not walk from the main entrance, but deliberately walked to Chen Zhou's side, either saying "Big guy, show mercy next time", or saying "Big guy, you are so handsome!".

Then left the classroom through the back door.

In this regard, Chen Zhou was also a little crying and laughing.

After everyone was gone, Chen Zhou got up and walked towards Zhang Zhongyuan.

Zhang Zhongyuan looked at Chen Zhou and asked, "How is it, this trip to MIT has been full of harvest, right?"

Chen Zhou shook his head: "It's not a full harvest, most of the time, I used it to study the Kramel conjecture, and I didn't even have time to listen to the report." ”

Zhang Zhongyuan suddenly laughed and scolded: "You kid is cheap and obedient, will those reports be listened to or not, will it have a big impact on you? Can you solve the Cramel conjecture?"

"Hey, hey. Chen Zhou laughed, "I can't say that, there are still many bigwigs' reports." Like Professor Faltins, Professor Deligne......"

"Stop, stop!" Zhang Zhongyuan felt that he should not bring up this topic.

After a pause, he asked again, "You have finished the paper of the Clamell conjecture?"

Chen Zhou nodded: "I have submitted the manuscript to the Annals of Mathematics." ”

"That's fine, it's another study that shocked the mathematical community. Zhang Zhongyuan glanced at Chen Zhou after speaking, and added, "Compared to those mathematicians who didn't go to the scene to listen to the report. ”

Seeing Zhang Zhongyuan like this, Chen Zhou smiled, how is this a little different from the Professor Zhang he is familiar with?

"I heard that you turned down Princeton's invitation, and that it was Professor Faltins' personal invitation. Zhang Zhongyuan asked the doubts in his heart.

"Hmm. Chen Zhou thought for a moment and explained, "Since Yanda has already been contacted, there is no need for me to change this. Moreover, the study of mathematics is mainly based on the individual, not that in Princeton, you will definitely be able to make good research. ”

Hearing this, Zhang Zhongyuan couldn't help but speak, this kid's consciousness is so high?

Sure enough, the person who can kill two world-class mathematical conjectures in a row is different, and he has the style I had back then.

But then, he heard Chen Zhou continue: "Besides, you don't have to go to Princeton to communicate with these great mathematicians, you can do it by email or phone." ”

"And when I go to Princeton, I guess the way of communication is the same, I don't believe it, they will be honest and wait for you to find it. Maybe it's better to send an email sooner. ”

Zhang Zhongyuan: "......"

After being silent for a while, Zhang Zhongyuan said: "Since you have decided, I won't say anything." Just like when I was younger, you have always been a person who has ideas of your own and can do them, believing that you can go your own way. ”

"Uh...... Professor, I'll think you're complimenting me......" Chen Zhou said with a smile.

Zhang Zhongyuan glared at Chen Zhou: "Of course!"

After separating from Zhang Zhongyuan, Chen Zhou went directly to Yang Yiyi for lunch.

Chen Zhou's purpose in going to this class was to relax on the one hand, and to "consolidate" his knowledge on the other.

Through different learning styles, there may be different gains, and it may not be possible.

Knowledge needs to be reviewed.

Reviewing the past and learning the new is not an empty phrase.

At the same time, Chen Zhou also wanted to see how he would feel differently when he learned mathematics knowledge after he was promoted to Lv6.

The result did not disappoint him, and he can always gain different content in small ways.

In the case of the proof question, he could think of at least three or more methods.

In the process of proof, he can also associate all kinds of different mathematical knowledge.

This is a manifestation of knowledge proficiency.

The Annals of Mathematics is published every two months, with no more than 100 articles per year.

It stands to reason that the last issue of the Annals of Mathematics in 2015 should not be published until late December at the earliest.

However, to Chen Zhou's surprise, he only submitted his paper for about a week.

The latest issue of the Annals of Mathematics was published.

And his paper "Proof of Clamell's Conjecture by Distributive Deconstruction" appeared in the latest issue of the Annals of Mathematics.

And it's the first article in this issue.

At the end of the paper, there is a line of reviewers' comments on the paper.

[This is not just a proof of the Kramel conjecture, but also the key to the prime interval problem, and if there is any reason for its importance, it is - this is an opportunity to parse number theory!]