Xueba starts with change

Chapter 291 Chen Zhou Is Missing?
Zhang Yitang's method is essentially a sieve method.

But a big problem with the sieve method is the so-called "parity problem".

To put it simply, if all the numbers in a set have only an odd number of prime factors, then it is impossible to effectively estimate how many elements the set has at least by using the traditional sieve method.

The set of prime numbers happens to belong to this type.

In order to break the curse of the parity problem, a suitable new method can be introduced into the traditional sieve method to make up for the defects of the upper sieve method.

And Zhang Yitang's starting point is "Goldston-Pintz-Yildirim" and "Bombieri-Friedlander-Iwaniec", the result of the work of these six people.

They are about the bounded distance and the distribution of prime numbers in the arithmetic sequence respectively.

This is the key to his solution.

In general, many people use theorems like they use computers.

They figured that if the theorem was true, fine, they could just use it.

However, what if it is the result of "not being flexible enough"?
Like the work of the "Bombieri-Friedlander-Iwaniec" trio, because it's "not flexible enough".

This will impose certain conditions on those who use the results of their work.

Because Zhang Yitang has a deep accumulation and a deep enough understanding of techniques, he was able to correct the work of the three "Bombieri-Friedlander-Iwaniec" and crossed the threshold of "not flexible enough".

He improved the "Bombieri-Friedlander-Iwaniec" analysis technique for the distribution of prime numbers into a tool for studying any kind of prime numbers.

This is a very complicated form of finding prime numbers.

As the prime interval increases, the gaps between the prime pairs obtained by previous sieve methods become larger and larger, because the inequality parameters they use to estimate are imprecise.

The "Goldston-Pintz-Yildirim" trio have used the previous sieve method to prove that there are infinitely many pairs of prime numbers.

The distance between them is always less than the average distance of consecutive prime numbers, but it is not possible to determine what this distance is.

However, Zhang Yitang's research partially succeeded in refining the selectivity of the sieve method.

A theory that began in the eighteenth century was further developed because of him.

Chen Zhou, who was immersed in his thesis, had already forgotten to eat lunch.

His eyes are now full of mathematical formulas.

My mind is full of inspiration at that moment.

Dean Sun and others who were still at MIT had already walked together again. They planned to have dinner with Chen Zhou, but they didn't see Chen Zhou after looking around.

Dean Sun had to take out his mobile phone and call Chen Zhou.

But what came on the phone was "Sorry, the number you dialed is turned off..."

Dean Sun couldn't help wondering, where did this kid go?

This foreigner, shouldn't he be taken away by someone?

The United States is not like what the world says, it is not a very safe country.

Seeing Dean Sun frowning and hanging up the phone, Zheng Chengyu asked, "Dean, what's the matter?"

Dean Sun said: "The phone didn't get through."

"Could it be that his phone ran out of battery?" Zheng Chengyu suggested a possibility.

Dean Sun said with a stern expression: "Let's look for it first..."

After finishing speaking, he took the lead in finding Chen Zhou.

Zheng Chengyu and the others quickly followed.

Soon, Zheng Chengyu and the others began to search separately.

Each person is responsible for a different area.

Only Zou Minwang still followed Dean Sun.

Dean Sun frowned when he saw Zou Minwang following him, but didn't say anything.

After accompanying Dean Sun to find the auditorium for the morning report, Zou Minwang said, "Dean, don't worry, he is such a big man, he can't get lost, right? And you can rest assured about the safety of the country of America. "

Hearing this, Dean Sun directly punctured his thoughts, and said in a stern tone: "Are you hoping that something happens to him? Have you forgotten that our Yanda students were killed in the country of America?"

Zou Minwang didn't expect Dean Sun to be so angry, so he immediately shut up.

But I still muttered in my heart: "I'm just telling the truth, and this kid is so unruly, if he really suffers, there's nothing wrong with it."

Of course, if he thought so, he wouldn't dare to say it even if he had ten more guts.

He followed Dean Sun obediently, looking here and there, as if he was looking for Chen Zhou.

In fact, Zou Minwang had nothing against Chen Zhou, but he just didn't like Chen Zhou.

As a college student, he has done too many special things at Yanda University.

And, as he said before, how should Yanda get along with such a genius?
After searching for a while, Dean Sun, Zheng Chengyu and others met again.

Several people shook their heads, but they couldn't find it.

In other words, Chen Zhou is not here at MIT.

"Dean, why don't you go back to the hotel and ask?" Zheng Chengyu suggested.

Dean Sun nodded: "Go back to the hotel first and have a look. If you are not in the hotel, please inform MIT and ask them to help you find it."

Just when Dean Sun and the others were about to go back to the hotel, Dr. James, who was in charge of the manuscript review, found them.

"Hi, Professor Sun." James greeted warmly.

If Professor Sun in front of him hadn't found him to communicate with his mailbox, he might have missed Chen Zhou's excellent paper.

That would be his great regret.

Seeing Dr. James, Dean Sun immediately said, "Dr. James, have you seen Chen Zhou?"

James was taken aback for a moment, and said immediately, "Isn't Chen with you guys? I'm also looking for him. I still have something to communicate with him about the report meeting the day after tomorrow."

Noticing Dean Sun's complexion is not very good, James asked again: "What's wrong? Has something happened?"

Dean Sun replied: "I'm afraid you can't find Chen Zhou for the time being, Chen Zhou is gone!"

Immediately, Dean Sun explained the whole process of Chen Zhou coming to the venue with them, separating after that, and finding no one.

James thought for a while, and then said, "Don't worry, I'll ask someone to ask, and you should go back to the hotel first, maybe Chen has already gone back."

After the words fell, James turned and left. He planned to find the staff in charge of the venue to find out the situation.

Dean Sun looked at the back of James leaving, and said in a deep voice: "Let's go back to the hotel, Zheng Chengyu, you stay."

Zheng Chengyu was taken aback, nodded immediately and said, "Okay, Dean."

But he felt a little strange in his heart. Logically speaking, shouldn't Zou Minwang stay and communicate with MIT at any time?

The hotel was arranged by MIT for this meeting, not far from the venue.

Although a few people did not drive to the venue like the day before yesterday, it was not too far to walk back.

As soon as he arrived at the hotel, Dean Sun hurried to the front desk and asked the lady at the front desk about the situation.

After asking about the situation, Dean Sun finally breathed a sigh of relief.

Fortunately, I didn't lose this kid!

If something happens, the consequences will be serious!

It's not that he doesn't believe in the safety of the United States, but after all, there are so many facts before him.

And no one can say, the probability of such an emergency.

After all, the safest place in Huaguo's heart is always in Huaguo!

(End of this chapter)