Beijing, mid-to-late January.

As time passed, the city of antiquity welcomed flights from all over the world, as usual.

There is a constant flow of people coming and going, but what is a little different from usual is that the lively atmosphere has some academic atmosphere.

With five students, Xu Chuan took the high-speed train to come here again.

He was urged by Mr. Qiu.

The old gentleman was probably afraid that Xu Chuan would forget to release the pigeons in the mathematics world at the 'International Symposium on the History of Mathematics and Mathematics Education', so he began to call him a few days in advance and ask him when he would come.

Although I understand Mr. Qiu's feelings, does he look like the kind of person who will release pigeons?

Apparently not.

So Xu Chuan chose to bring all five students to the capital, and they made an appointment to see the world.

Actually, give me more to eat at the banquet! Eat poor Mizuki University!

The first time I was taken by the tutor to participate in this kind of tall seminar, several students were like tails, and they followed Xu Chuan nervously, and they were students who had never seen the world.

Xu Chuan didn't care, and came to the hotel where the seminar was stayed.

I have to say that as the two top universities in China, Mizuki University is really generously funded.

Perhaps to showcase the charm and history of China in front of mathematicians from all over the world, the International Symposium on the History and Education of Mathematics provides a top-notch hotel for mathematicians to stay in.

The most distinctive feature of this hotel is that it is not in the form of a high-rise building, but an ancient courtyard house.

Entering this hotel, even Xu Chuan sighed a little, he was really rich.

Not to mention the few students who came with him to see the world, they were directly shocked.

Following behind his mentor, Cai Peng couldn't help but be stunned when he looked at the courtyard that could be said to be luxurious, and asked curiously: "Professor, do you usually live in this kind of place when you go on business trips?" ”

Beside him, the other four friends pricked their ears and listened curiously.

Xu Chuan shrugged his shoulders and said, "To be honest, it's the first time I've lived in this kind of courtyard house. ”

After a pause, just as he wanted to continue to add a sentence, an old man in a windbreaker with luggage walked in from the courtyard gate out of the corner of his eye.

Stopping the words in his mouth, he walked over quickly, and greeted with a smile: "Mentor, I didn't expect you to come too." ”

Hearing the voice, Deligne, who was dragging the suitcase, stopped, raised his head, and saw a rare smile on his face after seeing the familiar person in front of him: "Long time no see." ”

Xu Chuan nodded, took the luggage for Deligne, and said with a smile: "Yes, it's been two years." ”

Looking at the still young student in front of him, Deligne sighed with emotion: "I heard that Qiu Chengtong pulled a lot of old friends at this meeting, so I came over to take a look." ”

"And to be able to leave something for the math community in the later years of my life, that's what I should do."

Xu Chuan smiled and said, "Knowledge is never old or new, even if it is a method that has been replaced, it has also sparked in the history of civilization. It carries the dream of civilization and is a treasure worthy of all to remember. ”

After a slight pause, he continued: "And the old method, sometimes there are new uses, change the field, maybe it can shine again." ”

Hearing this, Deligne glanced at him with some curiosity: "Are you going to come up with something at this report meeting?" ”

He knew the student, and if he hadn't found something, he probably wouldn't have said that.

Perhaps, something interesting will be seen at this seminar?

Xu Chuan smiled mysteriously and said, "In this seminar, I will have a half-hour exchange report, and you will know when the time comes." ”

Hearing this, Deligne nodded and didn't ask.

It's just a day, and he can afford to wait.

January 20th.

In the auditorium of Mizuki University, the first International Symposium on the History of Mathematics and Mathematics Education kicked off.

Before it was nine o'clock, the auditorium of Mizuki University was already full of people.

Coming to the venue, Xu Chuan made his way through the crowd and found his seat as instructed.

To his surprise, next to him, sat another old man in a cardigan.

"I didn't expect you to come over, mentor, aren't CERN busy?"

Looking at the familiar old man, Xu Chuan was a little surprised.

The man sitting next to him was none other professor from his time at Princeton, Edward Witten.

If Professor Deligne's arrival was expected, then Witten's arrival really didn't surprise him.

Hearing Xu Chuan's inquiry, Edward Witten smiled and said in a somewhat mocking tone: "Although the outside world regards me as a physicist, I am an authentic Fields Medal winner, the kind with medals." ”

"If I wasn't qualified to attend this seminar, I can't think of anyone more qualified."

Hearing this, Xu Chuan couldn't help coughing dryly, he almost forgot that his mentor was the first to win the Fields Medal as a physicist.

was accidentally loaded by him.

But that's true.

After all, if even the Fields Medal winners were not able to participate, more than 99 percent of the people in this auditorium would probably have to quit.

With a dry cough, Xu Chuan sat down, chatting with Witten while waiting for the start of the report meeting.

At half past nine, the first International Symposium on the History of Mathematics and Mathematics Education officially kicked off in the auditorium of Mizuki University.

First, the organizer of the seminar, Mizuki University, gave a brief report on the normal process of the meeting.

Immediately, the IMU director of the International Mathematical Union took the stage to make a speech, giving a detailed speech on the research topics of "History of Ancient and Modern Mathematics", "Mathematical Communication and Communication", "Mathematics Education and Mathematical Culture", and called on all countries and the mathematical community to protect, disseminate, develop and promote mathematical culture.

Subsequently, the personnel of Huaguo Zhengfu came to the stage to make a report at the seminar, saying that Huaguo will make a contribution to better promoting the research of mathematical culture, promoting the development of mathematics, disseminating mathematical culture, and leading the direction of mathematical development.

The morning report didn't have much to look at.

The highlight was the afternoon meeting.

Mizuki University has provided three lecture halls for scholars who come to the symposium to do different exchanges.

Xu Chuan didn't wait long, after the afternoon exchange meeting began, the second report in the No. 1 lecture hall was his time, about half an hour or so.

Because of the charter, at about 3 o'clock in the afternoon, the No. 1 lecture hall was already full, and even some mathematicians who came to the conference sat directly in the aisle because they could not find a place.

When Xu Chuan walked into the lecture hall, he couldn't help but wonder if all the scholars who came to participate in the seminar this time were crowded.

After all, this number is too exaggerated.

Fortunately, he was also a person who had seen a big scene, and although he was a little surprised, he still walked to the podium very calmly.

After trying the microphone and confirming that there was no problem, he glanced around the lecture hall and saw quite a few acquaintances.

Smiling, he said slowly, "I am very welcome to all the scholars who have come from afar to participate in the symposium today. Today's exchange meeting is, in my opinion, a very meaningful event. ”

"Of course, I don't need to repeat what I said about the protection and development of mathematics, because I believe that the people who are here today are all passionate about mathematics."

"And the report I'm giving today, to be honest, is not from a purely mathematical point of view. What I am reporting is more about the application of mathematics and the physics in which it complements each other. ”

"There may be some people who don't understand today's report, but I believe it will be worth it and will not waste your energy and time."

Listening to Xu Chuan's words, there was a slight commotion in the lecture hall.

And Edward Witten, who was sitting in the front row, raised his eyebrows in some surprise after hearing these words.

In the math seminar, bring physics, which is probably the first person in history.

After thinking about it, he looked slightly sideways at Deligne, who was sitting next to him, and asked, "Do you know what he is going to report today?" ”

Deligne shook his head and said, "I don't know. ”

After a slight pause, he remembered the unexpected meeting with this student yesterday, and added: "But I'm looking forward to it." ”

Xu Chuan didn't care about the commotion in the audience, he continued: "After thousands of years of development, the ancient discipline of mathematics has opened up many branches in the past 100 years and produced a number of applied disciplines. ”

"But looking back at history, the development of mathematics has often benefited from the problems raised by physics, and every major revolution in physics has often been accompanied by the introduction of new mathematics."

"The two complement each other."

"Some time ago, when I was researching some problems, I accidentally made some new discoveries. Today, I would like to share these results to add a touch of color to this workshop. ”

"Of course, it will be more in the field of mathematical physics, and it may be a little difficult for scholars who are not in this field to understand, but I will try to report it in the most concise words possible."

As he spoke, he turned on the projector behind him.

A silvery-white curtain slowly falls vertically.

After waiting for a few seconds, a gentle white light lit up on the curtain, and a clear line of titles emerged from the silvery white curtain.

[Mathematical Theory of Non-equilibrium Strongly Correlated Electronic Systems and a Calculation Method for a Specific Correlation Type!] 】

A line of black block letters jumped into everyone's eyes.

Of course, considering that most of the scholars present are international scholars, there is also a line of English under the block letters.

When the clear title appeared in the eyes of Professor Witten, who was sitting in the front row, on the silver-white curtain, his brown and black pupils contracted violently, and he couldn't help but exclaim in a low voice:

"Mathematical theory of non-equilibrium strongly correlated systems, how is this possible?"

On the side, Professor Deligne, who was sitting next to him, noticed his movements, turned his head to look at him, and asked curiously, "What's wrong?" ”

PS: Yesterday's three watches, ask for a monthly pass! There are two more today! Let's get some monthly passes, big guys (●''●)