Zhang Yitang's method is essentially a sieve method.

But one of the big problems 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 not possible to effectively estimate how many elements there are in the set using the traditional sieve method.

And the set of prime numbers happens to belong to this type.

In order to break the curse of parity, suitable new methods can be introduced into the traditional sieve method to compensate for the shortcomings of the upper sieve method.

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

They are about the distribution of prime numbers in a series of bounded distances and equal differences.

This is the key to solving the problem.

In general, many people use theorems as if they were computers.

They think that if the theorem is correct, that's fine, and they can just use it.

But what if it's a "not flexible enough" outcome?

Like the work of the trio "Bombieri-Friedlander-Iwaniec", because it is "not flexible enough".

This will make it necessary for people who use their work to have certain strings attached.

Because Zhang Yitang has a deep accumulation and a deep understanding of skills, he was able to correct the work of the "Bombieri-Friedlander-Iwaniec" trio and crossed the threshold of "inflexible".

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

This is a very complex form of finding prime numbers.

As the prime interval increases, the gap between the prime pairs netted by the previous sieve method grows larger and larger, because the inequality parameters they use to estimate are not accurate.

The "Goldston-Pintz-Yildirim" trio has demonstrated the existence of an infinite number of prime pairs using the previous sieve method.

The distance between them is always less than the average distance of successive primes, but it is not certain what this distance is.

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

Theories that began in the 18th century were further developed thanks to him.

Chen Zhou, who was immersed in the paper, had forgotten to eat lunch.

His eyes are now full of mathematical formulas.

My mind is full of inspiration for that moment.

Dean Sun and others, who are still at MIT, have already walked together again, and they originally planned to find Chen Zhou to eat together, but they didn't see Chen Zhou after looking around.

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

But the phone call said "Sorry, the phone you dialed is turned off......"

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

This foreign country should not be taken captive, right?

This is not like the international community, it is not a very safe country.

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

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

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

Dean Sun said with a grim face: "Let's look for ...... first"

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

Zheng Cheng met them and hurried to follow.

Soon, Zheng Chengyu and they began to look separately.

Each person is responsible for a different area.

Only Zou Minwang still followed Dean Sun.

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

After accompanying Dean Sun to find the auditorium of the morning report meeting, Zou Minwang said loudly: "Dean, you can rest assured, he is such a big person, he can't run away, right?" ”

Hearing this, Dean Sun directly punctured his thoughts, and said in a stern tone: "Do you wish that something would happen to him? Have you forgotten that our students of Yan University were killed in the United States?"

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

But he was still muttering in his heart: "I'm just telling the truth, and this kid is so unruly, it's not bad if he really suffers." ”

Of course, if he thinks so, he will not dare to say it if he is given ten more dares.

Honestly follow behind Dean Sun, take a look here, look at that, and treat it as looking for Chen Zhou.

Zou Minwang actually doesn't have any bad relations with Chen Zhou, but he just doesn't like Chen Zhou.

A college student has done too much special things in Yan University.

And, as he said earlier, how should Yan Da get along with such a genius?

After looking 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, do you want to go back to the hotel and ask?" Zheng Chengyu suggested.

Dean Sun nodded: "Go back to the hotel first, if you are not in the hotel, inform the MIT side and ask them to help find it." ”

Just as Dean Sun and the others were about to return to the hotel, Dr. James, who was in charge of the review, approached them.

"Hi, Professor Sun. James greeted him warmly.

If it weren't for Professor Sun in front of him to find his communication email, he would probably 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 stunned for a moment, and then said: "Isn't Chen with you? I'm also looking for him, about the report meeting the day after tomorrow, and there are still some things that need to be communicated with him." ”

Noticing that Dean Sun's face was not very good, James asked again, "What's wrong?

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

Immediately, Dean Sun told Chen Zhou and them about the whole process of coming to the venue with them, and then separating until they couldn't find anyone.

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

As soon as the words fell, James turned and left, intending to go to 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 will stay with you." ”

Zheng Chengyu was stunned for a moment, and immediately nodded: "Okay, dean." ”

But he was a little strange in his heart, it stands to reason that Zou Minwang should stay and communicate with MIT at any time?

The hotel was arranged by the Massachusetts Institute of Technology for this conference and is not far from the venue.

Although a few people did not drive to the venue as the day before yesterday, they did not walk far back.

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

It wasn't until he asked about the situation that 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 security of the United States, but after all, there are so many facts in front of him.

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

After all, the safest place in the hearts of Chinese people is always in Huaguo!