In the discussion of all the mathematicians in the audience, Lin Yu sorted out his thoughts, came to the whiteboard, picked up the black marker, and then opened the super brain without hesitation to write.

Let v(x,t) be a three-dimensional vector field describing the fluid velocity, and p(x,t) is the fluid pressure, and the Neville-Stokes equation is: αv/αt+(v·▽)v=—▽p+vΔv+f(x,t).

Wherein: v>0 is the dynamic viscosity; f(x,t) is the external force; ▽ is a gradient operator; Δ is the Laplace operator.

The above equation is a vector equation, which can be decomposed into three equations of pure quantity, and the velocity and external force are decomposed into the components under the three coordinates:

v(x，t)=[u1(x，t)，u2(x，t)，u3(x，t)]

f(x，t)=[f1(x，t)，f2(x，t)，f3(x，t)]

Then the Navier-Stokes equation can be written in the form of...

………

When Lin Yu first started to solve the problem, everyone present was unimpressed.

Because Lin Yu's solution idea is very general, he uses the sieve method commonly used by all mathematicians to derive.

In the entire mathematical community, countless mathematicians use this common method every day to deduce the NS equation, but none of them can successfully deduce it to the end.

Because the amount of mathematical formulas and calculations required is amazing.

Even the top mathematicians in the field of mathematics, such as Deligne, have chosen to put aside this kind of world-class problem that cannot be solved by manpower.

Therefore, they prefer to devote their time and energy to other world problems rather than solving such global problems that are impossible to prove mathematically.

Because even the study of the world's seven millennial puzzles is better than the study of the Navier-Stokes equation.

After all, with the exception of the Navier-Stokes equation and the p and np problems, the world's seven millennial problems are basically progressable.

Even if this progress is not really useful for solving the problem.

However, as long as someone overcomes it and someone finds the problem, sooner or later there will be progress in solving the problem.

Over time.

However, when everyone took it for granted that Lin Yu should also sink into the sand, their eyes suddenly widened, and their eyes stared directly at the whiteboard on the report table.

"Lao Chen, look at the sieve method used by Lin Yu's kid, it seems to be a little different from the sieve method that is common in the mathematical world now?"

On the seat, Qiu Chengtong stared at the whiteboard on the report table with his eyes firmly on the desk, and asked suspiciously without looking back.

"Indeed, the sieve method he uses now is different from any sieving method that is prevalent in mathematics."

The old man nodded solemnly.

After pondering for a moment, the old man Chern seemed to have thought of a possibility, and said in his tone with uncontrollable excitement and trembling: "I can see it!" His sieving method seems to be a brand new sieving method! It is a new sieve method that has never appeared in the mathematical world at present!! ”

As we all know, there are three sieving methods that are most commonly used in mathematics today.

The first is the o(n√n) violent screening method (n≤2e5).

It can determine whether there are factors one by one, and then filter it, which is the most commonly used method, and it is very convenient when the complexity is small.

The second is the most classic o(nlog2n) Åss sieve (n≤1e6).

It can sieve out multiples of each number, and it is divided into large sieving method, small sieve method and so on.

As for the third type, it is o(n)Euler sieve (n≤1e8)

These three sieving methods are very commonly used in the mathematical community, and they can be used to solve most of the problems that are needed in the mathematical community.

Of course, in addition to these, there are many special sieving methods that require a very small range of sieving, such as min_25 sieving and so on.

It's just that the sieving methods that Lin Yu uses now are not any of them!

"A new sieve method!?"

After listening to the words of the old man Chern, the old man Qiu Chengtong next to him was suddenly shocked in his heart.

He couldn't take care of Lin Yu who was still solving the problem on the stage, and the whole person subconsciously looked at the old man Cherry next to him, with a shocked face.

A new sieve method that represents more than just proving a conjecture!

It represents a revolution in mathematical tools!

It is no exaggeration to say that its appearance is enough to make it possible to solve countless unsolved mysteries in the mathematical community again!

With it, the whole development of mathematics will be a big step forward!

Even, Lin Yu's name and this new sieve method will be engraved into the history of mathematics!

And as long as Lin Yu is willing, the name of this new sieve method will be named after his surname!

At this moment, it was not only the two old men who were shocked, but even the top Princeton math bigwigs such as Deligne, who were sitting in the front row, were shocked by the new sieve method displayed by Lin Yu on the lecture platform.

"Farr, do you see that?" A big smile appeared on Deligne's face.

"Well, a new sieve method."

Faljans continued in a heavy tone: "I can see the shadow of the heavy sieving method and the Ehrlich sieving method from this new sieving method, as for whether there are other sieving methods, I don't know, but at present, it seems that the effect of this new sieving method is very strong. ”

"Because it almost combines the advantages of many sieving methods, and the most powerful thing about it is that the disadvantages of those comprehensive sieving methods have all been abandoned, not even the slightest disadvantage, it is simply very perfect, so perfect that it is not at all like human beings can achieve it."

At the end of the words, Faljans shook his head with a sigh and looked at Lin Yu on the report table with a complicated expression.

To be honest, he has been in the mathematical world for so many years, and this is the first time he has seen someone with such perverted abilities.

is so perverted that it simply refreshes his definition and perception of genius.

"Faljens is right, this new sieving method is just perfect."

Just after Faljans's words fell, Andrew Wiles next to him also sighed and said: "Actually, I once thought of synthesizing the advantages of the sieve method in mathematics like Lin Yu, but it is too difficult, even if I try to deduce tens of thousands of times, I can only roughly synthesize the heavy sieve method and the large sieve method in the Ehrlich sieve method." ”

Speaking of this, Andrew Wiles couldn't help but glance at Lin Yu on the report table with admiration, and then continued with a wry smile: "And my rough combination of the advantages of the two sieving methods, compared with the new sieving method that Lin Yu is now expressing, is almost like the horse-drawn carriage in the 17th century and the current high-speed rail, the gap between the two is really too big......"

After that, Andrew Wiles sighed helplessly.

And after listening to the words of the two, the eyes of many of the top math bosses around them also flashed with complex light.

There is surprise and envy, but more is the appreciation and admiration of the younger generations.

"As long as Lin Yu can successfully find a weak solution to the Navier-Stokes equation, he will be the one who will win this year's Crawford Prize."

"Not to mention the Claude Prize, this new sieve method alone is enough to nominate Wolf and Fields!"

"If only he could stay at Princeton, working with this kind of young man who is never short of inspiration, it's energizing to think about..."

"Hehe, I'm afraid that's impossible, listening to Deligne, this young man loves his wife very much, and even Deligne personally invited, he did not hesitate to politely refuse."

"Alas, what a pity......"

Just when many top math bosses in the front row were casually watching Lin Yu's problem-solving process on the stage, they were discussing lively.

The other mathematicians in the lecture hall were not so easy.

The reason is very simple, they only saw Lin Yu writing the whiteboard, but they didn't understand the proof process written by Lin Yu with the new sieve method.

"Hey, Jack, do you understand?"

On the seat behind him, a blonde and blue-eyed young man patted the blonde man wearing gold-rimmed glasses next to him, and looked at one of the arithmetic formulas on the whiteboard of the report table in a daze.

The blonde man known as Jack didn't seem to feel the actions of his companion next to him.

After a long time, his contemplative face relaxed, and he shouted excitedly, "I understand!" I get it!! ”

However, after a while, he looked at the equation in the notebook on his lap with a sad face, and muttered to himself, "But I really think I miscalculated..."

After seeing this scene, the companion next to him couldn't help but shake his head helplessly, and immediately continued to work hard to study the equation on the whiteboard.

Such a scene can be seen everywhere in the lecture hall, and many young people are dejected and calculating an equation written by Lin Yu.

Even some of the old professors are stumped by some of these equations.

One by one, they wore reading glasses, and while they kept deducing in their notebooks, they also searched for information from the Internet.

For a while, as more and more writing sounds sounded, most of the people in the entire report hall fell into a state of flow with a focused expression.

Sometimes they are ecstatic, sometimes discouraged, sometimes solemn.

As the minutes ticked by, the equations on the whiteboard became more and more.

Soon, the specially made, five-meter-long whiteboard on the report table was filled with all of it by Lin Yu.

As early as when Lin Yu was about to finish writing, the staff not far away had already quickly brought up a five-meter-long whiteboard.

Therefore, Lin Yu did not pause at all, and he continued to write quickly on another whiteboard.

In summary, we can obtain a system of momentum equations in the x, y, and z directions:

α（pv·x）/αt+α（pv·x，pv·x）/αx+α（pv·y，pv·x）+α（pv·z，pv·x）＝fx（αoxx/αx+αtyx/αy+αtzx/αz)……

——————（10）

Obviously, the number of the above equations is less than the number of unknowns, the system of equations is not closed, there is no solution, and other equations need to be introduced to make the system closed.

Therefore, on the basis of the above system of equations, the following constitutive equation is introduced, that is, the relationship between stress and velocity is established.

αxx＝-p+2u·αvx/αx-2/3u(αvx/αx +αvy/αy+αvz/αz)

αyy＝-p+2u·αvy/αy-2/3u(αvx/αx +αvy/αy+αvz/αz)

αzz＝-p+2u·αvz/αz-2/3u(αvx/αx +αvy/αy+αvz/αz）……

——————（11）

So the simultaneous equations (10) and (11) can be obtained in the complete form, the vector form of the constant viscosity ns equation......

……

Fifty lines, eighty lines, one hundred and twenty lines......

In Lin Yu's state of full firepower, in less than twenty minutes, the space on the five-meter-long new whiteboard bottomed out again.

In desperation, the staff had no choice but to continue on the whiteboard.

With Lin Yu's crazy writing, when he wrote about the one hundred and fiftyth line, the top math masters in the front row, Deligne, were finally a little struggling.

The next moment, they took out the notebooks they had prepared a long time ago, put them on the table, and began to deduce them with serious expressions.

And as they also deduced, in an instant, the entire lecture hall where mathematicians gathered suddenly became quiet, and only the sound of clear writing continued to sound.

For a while, everyone seemed to have returned to their student days, all of them lowered their heads and calculated seriously.

In the face of this familiar situation, many staff members were also cautious, for fear of disturbing everyone.

"Lao Chen, do you think he can succeed?"

On the seat, Qiu Chengtong had already given up the deduction, he looked at Lin Yu who was writing the report table with bright eyes, and whispered to the old man Chern next to him.

Hearing this, the old man Chern thought about it seriously, then nodded slowly, and said seriously: "If even he can't calculate it, then I can only say that it must be a problem with this topic." ”

As for whether Lin Yu can prove the Navier-Stokes equation, Old Man Chern is sure in his heart.

Because since the Riemann conjecture, which is one of the world's seven millennial problems, has been successfully proved by Lin Yu, it is impossible for the Navier-Stokes equation to prove unsuccessful!

Although it is said that the process may last a little longer.

However, Mr. Chern always firmly believed that Lin Yu would prove his success.

Time passes slowly in this quiet atmosphere.

As more and more people gave up deduction, everyone's hearts began to get nervous.

Although the vast majority of people present were in a fog, they couldn't tell whether Lin Yu's proof process was correct or not.

However, Lin Yu's ability to write down these hundreds or thousands of lines of calculations is amazing enough.

An hour and a half later......

Just as Lin Yu was writing to the eleventh five-meter-long whiteboard, the person in charge of logistics of the report meeting ran anxiously to Deligne, who was deducing: "Professor Deligne, our characteristic whiteboard has been written, and the ordinary whiteboard is also being delivered urgently, but it will take a while to reach the lecture hall,"

His thoughts were interrupted, and Deligne quickly came back to his senses and asked with a serious expression, "Then do we have any other ordinary blackboards, or ordinary whiteboards?" ”

"The lecture hall is gone, but there should be classrooms in Princeton, as well as in the Princeton Promenade." The person in charge said truthfully.

"Okay, then you can arrange for someone to bring me all the free whiteboards and blackboards at Princeton University!"

"No matter what happens today, we must not interrupt the verification process of the Navier-Stokes equation, because this scene will be enough to go down in the history of mathematics!" Deligne's eyes looked feverishly at Lin Yu, who was checking on the report table, and said in a resolute tone.

"Understood!"

The person in charge looked stunned, and immediately quickly took out the walkie-talkie and ran quickly outside.

Purple Pen Literature