"Of course you can ......"

Looking at Professor Feverman unexpectedly, Lu Zhou made a gesture of please and gave up his position in front of the whiteboard.

Picking up the marker, Professor Feverman stared at the whiteboard for a moment before writing on it.

It's time for the end of class, but no one in the classroom has left their seats.

Including Lu Zhou, everyone stared intently at the content on the whiteboard.

Gradually, looking at Professor Feverman's steps, Lu Zhou's eyes lit up slightly.

Wonderful......

That's where the math comes in.

An idea that doesn't work, no matter how long you walk on it, you can't get out of the maze.

However, a seemingly viable line of thought, which doesn't even need to be close to the exit, can create the feeling that victory lies ahead from the moment you step into it.

Although Feverman has not yet written the last step, Lu Zhou can basically be sure that his thinking is not absolutely correct, but there is at least a ninety percent probability that it is feasible!

Sure enough, this big bull did not disappoint him.

Smoothly filling the remaining area of the whiteboard, Professor Feverman drew the last stroke on the last line-

【Pμi：=μi-(Δ^-1)·δi·δj·μj】

There was a commotion in the classroom, and while it was difficult for undergraduates, it was Princeton, and it was the math students at the top of the chain of disdain.

Just because you can't think of this step doesn't mean that no one can understand it.

Obviously, although they reacted a little slower, like Lu Zhou, they also saw the ingenuity of this line of thought from Professor Feverman's steps.

Retracting the marker pen printed on the whiteboard, Professor Feverman carefully read the equation he had written down from beginning to end, then smiled and whispered.

"It's not an easy question...... It's a little more difficult for undergraduates. ”

Lu Zhou coughed lightly: "So, it's just a reflection question." ”

He had only planned to meet with the students, and if it weren't for the fact that so many people were interested in his research progress, he wouldn't have put the question on the whiteboard on a whim.

What he didn't expect was that this big guy would sit in the back row of the lecture hall.

Returning his attention to the contents of the whiteboard, Professor Feverman said thoughtfully, touching the stubble on his chin.

"where (Δ^-1)·δi·δj is defined as the Fourier multiplier of ξiξj/|ξ|²...... But what I want to know is, even if you come up with the equation for Pμi, what's the point? I can't see it...... Can you answer it for me? ”

"Of course," this is not something to hide, Lu Zhou smiled and said happily, "However, I need a new whiteboard." ”

"The last thing Princeton lacks is a place to board books, I'll help you get one."

With these words dropped, Professor Feverman turned around and left the lecture hall without stopping, quickly dragging a whiteboard back from the next classroom.

Seeing the whiteboard that Professor Feverman dragged for him, Lu Zhou was no longer polite, wiped the handwriting on the whiteboard, picked up the marker again and started the board book, and explained his steps in detail.

"If we get Pμi:=μi-(Δ^-1)·δi·δj·μj, we can further find the ...... by using the non-divergent properties of μ for conventional integrals."

During this time, he has been busy with experiments, and the research on the NS equation has actually only been carried out to the point of "Pμi:=? "This step, as for the content of the next board book on the whiteboard, is actually derived on the spot.

It may sound like a bit of a struggle.

But it's actually quite easy to do that.

After all, the idea is here, and all he needs to do is bring in the conclusions he has previously reached, and then continue to deduce along this line of thought.

However, this kind of ease is not endless......

【〈B（μ，v），〉=-πi∫Λξ1，ξ2，ξ3（μ（ξ1），v（ξ2），（ξ3））……】

Writing this line of calculation on the whiteboard, the tip of the pen in Lu Zhou's hand suddenly stopped.

Seeing this step, Professor Feverman's originally tightly knit eyebrows suddenly provoked a trace of interest arc.

Lu Zhou withdrew the marker pen in his hand and cast an inquiring glance at him.

"What do you think?"

The index finger rubbed thoughtfully against the stubble, and Professor Feverman said as if to himself.

"Like...... It's kind of interesting. ”

The eyes looked at the two people on the podium without blinking, and the students sitting in the classroom were silent, for fear of making a little noise and interrupting the thinking of the two big guys.

There is probably no place in all of North America that respects genius and knowledge more than Princeton.

Five minutes had passed, and Professor Feverman's face suddenly relaxed, and he said in a relaxed tone.

"It seems that this problem is not so easy to solve."

Lu Zhou, who stared at the whiteboard intently, nodded in agreement: "You're right." ”

If it were such a good solution, the Clay Institute would not have included it in the list of the seven millennial problems.

"But you can do this far beyond my expectations." Smiling, Professor Feverman said kindly, "The NS equation is a very interesting problem, it is the basis of fluid mechanics, and it is also a classic proposition in partial differential equations. If the overall existence of its smooth solution can be solved, it will not only be for the glory of the human mind, but will have a profound impact on a series of related disciplines. ”

Dieudone was one of the founders of the Bourbaki school, and "mathematics is for the glory of the human mind" is exactly what he once said. Professor Feverman, while not agreeing with the Bourbaki school, agrees with it.

At this, Professor Feverman smiled and clapped his hands.

"It was a very fulfilling lesson...... Although I may be a bit boastful of saying this. What do you think? ”

At the end of the sentence, he looked back at the classroom, and the people who hadn't moved their farts off the bench even though class had already ended. shares of students.

And in response to him, of course, there was applause from the classroom.

Listening to the thunderous applause, Lu Zhou smiled embarrassedly.

Although he didn't speak, he actually felt a little proud in his heart.

Compared with a serious presentation, the sense of accomplishment that the classroom brought to him was a completely different experience.

It seems that even though he hasn't seen each other much throughout the semester, his students still like him.

"By the way, I've made this question," Listening to the applause in the classroom gradually subside, Professor Feverman suddenly remembered something, pointed to the equation on the whiteboard, and said in a humorous tone, "Is your promise still useful?" ”

Lu Zhou was slightly stunned and wondered.

"Promise?"

Sitting in the front row, the chestnut-haired girl who had asked him the first question raised her hand and said with great interest.

"Professor, you said that if anyone makes this question, you will accept him as your doctor."

There was a heckling in the classroom.

Lu Zhou didn't look at the student who took the lead in coaxing, and coughed dryly and said, "Don't be joking." ”

"No, no, no, I'm not kidding," Professor Feverman laughed, "and if you don't mind taking another Ph.D., I don't mind another Ph.D. from you." ”

Although Professor Feverman's tone didn't look like a joke, Lu Zhou knew he was definitely joking.

Compared with Professor Faltins, who has left Princeton, Professor Feverman is completely on the other extreme in terms of "arrogance". At the Institute for Advanced Study in Princeton, which is full of geniuses, he is the only one who will make such a joke without regard for his identity.

Seeing Lu Zhou's helpless expression, Feverman coughed lightly, stopped joking, and changed to a serious tone.

"Well, since you're not going to take another doctor, I want you to grant me a request."

Lu Zhou didn't promise easily, but asked, "What request?" ”

"Regarding the existence and smoothness of the solution of the three-dimensional incompressible Navier-Stokes equation," after a pause, Professor Feverman smiled and said in a sincere tone, "I hope to work with you to solve this problem!" ”