Chapter 298

September 20th.

The twelfth day of the conference.

The International Congress of Mathematicians has entered the final stage so far.

Of the more than 5,000 mathematicians who attended the conference, about one-third have already left for China.

The remaining more than 3,000 mathematicians did not spend all day in the conference building, but chose to take a walk around Yanjing under the leadership of the reception staff, and had the right to take a trip abroad.

The conference building became empty.

This allowed Gu Lu to blend in smoothly without being recognized.

There are many mathematicians who have seen Gu Lu's photos, but Gu Lu can disguise himself and get through the test perfectly.

Of course, this is also the reason why everyone never thought that Gu Lu, who had been staying at home and not going out, would suddenly come back with a horse and shoot back.

Of the 20 conference venues, Gu Lu has not been to 18 of them.

Gu Lu planned to go around one by one.

Gu Lu was the first to go to the functional analysis session.

Functional analysis is a large branch of mathematics.

It is juxtaposed with the major branches of mathematics such as geometry, number theory, and topology.

It includes theories such as nonlinear functional analysis, operator theory, operator algebra, and functional equations.

However, the functional analysis branch of mathematics has been born for a relatively short period of time.

In fact, it was only in the nineties of the last century, that is, thirty years ago, that a new branch of mathematics was officially created.

In just three decades, the development of functional analysis has been limited.

As a result, there was only one sub-session for the entire field of functional analysis at the conference.

The conference is coming to an end.

In the whole conference room, the pomp and circumstance of the past are not the same.

There were only about 100 people in the conference room, and all of them were listless and bored.

There were even some mathematicians who took out their mobile phones and played, completely ignoring what the person on the stage was talking about.

Gu Lu, as before, sneaked in at the back door.

The back rows are completely empty.

Gu Lu casually found a place and sat down.

Then, look up at the lecture stand.

So far, the 45-minute presentations in all the sub-sessions have ended.

The current reports are all ten-minute reports requested by mathematicians of all branches.

As for Gu Lu, applying for the next 45-minute report, it has never happened again.

Gu Lu helped the pair of unqualified eyes on the bridge of his nose to hide his appearance, and his gaze fell on the young man who was standing on the stage and was making a report.

That young man was older than Gu Lu, but he should be less than thirty years old.

Obviously, it was the first time for that young man to appear on such a big stage, and his expression was a little nervous, and his speech was still stumbling.

But what the young man told aroused Gu Lu's interest.

The content of this young man's report belongs to the operator theory aspect of functional analysis.

"From Generalized Weighted Bloch Space to Integral-type Operator of Bloch-type Space"!

This is the subject of the young man's report.

The main content of the study is to study the boundedness and compactness of the integral operator P(g,φ) from the generalized weighted Bloch space to the Bloch-type space on the unit sphere.

The reason why Gu Lu is interested is.

At the end of the report, on the basis of research, three new theorems were proposed.

And one of the theorems made Gu Lu see its difference.

Since the reporting time is only ten minutes.

The content of the youth report is not too complex.

With the deliberate acceleration of the youth, it took only about eight minutes for the youth to finish the content of the report.

This was followed by the regular Q&A session.

The young man glanced at the audience and asked nervously and expectantly, "Do you have any questions, can you raise your hand to ask questions now?"

Silence, silence.

There was no one below to take care of the youth.

It can be said that among the nearly 100 people in the audience, there are not a few who have just listened carefully to the content of the youth report.

The young man's expression was a little embarrassed and embarrassed.

He stood on the stage, not knowing what to do next.

Just when the young man's face was full of ashes and he was about to step off the stage, he suddenly saw the last row of the conference room, and one hand was slowly raised.

"I have a problem!"

Gu Lu's voice was not so loud as it echoed in the silent conference room.

Everyone turned their heads to look behind them in confusion.

Then I saw a young man wearing a mask, glasses, and a peaked cap on his head standing up from the back row of the conference room.

Who's this?

Many people have doubts in their hearts.

Dressed up so well, he sat at the back of the conference room.

It can't be sneaked in!

But it shouldn't!

It is not clear how strict the inspection at the entrance of the conference building is, and if you don't have a certificate, you will basically not be released.

Everyone was attracted by the strangely dressed Gu Lu for a while.

And the young man standing on the stage looked at Gu Lu with gratitude in his eyes as if he had grasped a life-saving straw.

Young people don't expect Gu Lu to ask high-quality questions.

Just ask someone to alleviate his current embarrassing situation.

The young man hurriedly asked the waiter to hand the microphone to Gu Lu.

Gu Lu took the microphone.

The young man took a deep breath and asked nervously, "What's wrong with you?"

Gu Lu smiled slightly, "The question I want to ask is about theorem three of the three theorems you proposed at the end. ”

"Theorem three?" the young man was slightly stunned.

The specific content of theorem 3 proposed by the youth is as follows:

[Let μ be normal, g∈H(b), g(0)=0, φ is the analytic self-mapping on the unit sphere B, α> 1, then P(g,φ):B(α,log)→ Bμ are compact operators, if and only if g∈H(∞,p).

supμ(z)|g(z)|A(|φ(z)|) ＜∞】

That's what Theorem Three is all about as described by the youth.

In the eyes of young people, this is just an ordinary conclusive theorem, and there is nothing special about it.

The young man didn't know why Gu Lu was asking this.

Of course, Gu Lu didn't know the doubts in the young man's heart.

He just wanted to say the thought in his heart, "When you came up with this theorem, didn't you think that this theorem has a lot to do with the bounded operator?"

"Bounded operators?"

"That's right, it's a bounded operator!" Gu Lu's tone was firm.

Bounded operators can be said to be the most popular research direction in the field of functional analysis.

The young man couldn't understand why his theorem was related to the bounded operator.

What he's researching is obviously a tight operator!

Fortunately, Gu Lu answered the doubts in the young man's heart in a timely manner.

"You can take the case of f=1 by defining the tight operator, so that you can easily get the boundedness of P(g,φ) and B(α,log), which is the first step. ”

Gu Lu raised his second finger and slowly spoke with a smile.

"As for the second step, for any bounded sequence f(k) in B(α,log), we get a fk→0 that is consistent on the tight subset of B, then ......"