The tarmac was densely packed with hundreds of people standing.

"How can there be so many people?"

Pang Xuelin looked at the crowd on the tarmac with some surprise.

Liu Tingbo also tilted his head, looked at the scene outside the porthole, and said, "Professor Pang, they should all come to greet you." ”

"Greet me?!"

Pang Xuelin was a little incredible.

This pomp and circumstance is even higher than last year's Nobel Prize ceremony.

What can those nerds in math do?

Liu Tingbo seemed to see Pang Xuelin's thoughts, and said with a smile: "Professor Pang, I am afraid that you have underestimated your own influence in the mathematical community. Not to mention anything else, how many mathematicians are studying Ponzi geometry in the world today, and in our school's Ponzi geometry seminar, young scholars in the field of mathematics want to come in, and there are only a dozen places every year, and now many young mathematicians regard you as their idol......"

Pang Xuelin nodded thoughtfully.

Although in the outside world now, after ordinary people hear Pang Xuelin's name, they will immediately associate this name with lithium-air batteries and the Nobel Prize.

But in the eyes of the mathematical community, Pang Xuelin is not doing his job.

There are many mathematicians who believe that if Pang Xuelin does not make any lithium-air batteries and superconductors, it is entirely possible to achieve greater achievements with his talent.

"Some people even said that if Pang Xuelin concentrates on mathematics, he is expected to become the god of mathematics."

This phrase first came from Faltins, the German stubborn old man said in an interview with the media that Pang Xuelin is another super genius in the mathematical world after the 20th century algebraic geometry Pope Grothendieck.

Then, he added: "It's a pity that this guy doesn't do his job, otherwise, he would have been able to become a god in mathematics." ”

After Pang Xuelin heard this evaluation, he could only shake his head and smile bitterly.

I don't know if I can meet this old man at this International Congress of Mathematicians.

The airliner slowly stopped on the tarmac, the aircraft door opened, and the ramp truck slowly connected to the plane.

Then, the accompanying flight attendant said, "Professor Pang, you can get off the plane." ”

Pang Xuelin nodded, and under the leadership of the flight attendant, got up and walked out of the plane first.

The crowd on the tarmac cheered.

Pang Xuelin walked down the gangway.

Two people walked in front of them, one was tall and thin, with bald hair, and the other had a big belly, only one meter and six meters tall, and they walked and swayed, looking a little funny.

The bald old man took the lead in stretching out his hand and said: "Hello, Professor Pang, welcome to St. Petersburg, I am Marcelo Viana, Chairman of the Organizing Committee of the International Congress of Mathematicians in St. Petersburg. ”

"Hello, Mr. President."

Pang Xuelin smiled and shook hands with Marcelo Viana.

Immediately afterward, he turned his gaze to another pot-bellied old man and said with a smile, "Hello, Chairman Kenny. ”

The pot-bellied old man smiled and said, "Professor Pang, I finally looked forward to you." ”

Carlos Kenny, a professor at the University of Chicago, a member of the American Mathematical Society, and the current president of the International Mathematical Union.

Next, Pang Xuelin, led by Marcelo Viana and Carlos Kenny, shook hands and greeted the bigwigs who came to welcome him one by one.

Among them are some bigwigs of the International Union of Mathematicians, as well as political leaders such as the Deputy Minister of Foreign Affairs of Russia and the mayor of St. Petersburg.

At the same time, Perelman and Shinichi Mochizuki, who were following Pang Xuelin, also shook hands with the people who greeted them one by one.

Even compared to Pang Xuelin, back at his home turf, Perelman was more welcomed.

After all, Perelman is also a long-established bigwig, and he is also a native of St. Petersburg, and not long ago he cooperated with Pang Xuelin to solve the Hodge conjecture.

Especially in the recent world of mathematics, Perelman is second only to Pang Xuelin in the limelight in a sense.

If it had been two years ago, Perelman might not have been able to accept such an occasion at all, so he would have ignored it and walked away.

However, after two years in Jiangcheng and occasional contact with scholars from the Ponzi Geometry Seminar, his withdrawn temperament improved a lot.

Coupled with the fact that this is St. Petersburg, Perelman's hometown, and returning to a familiar environment, Perelman reluctantly accepted the welcome ceremony.

Afterwards, everyone boarded the convoy arranged by the Russian side and went straight to the hotel.

In the evening, the Organizing Committee of the International Congress of Mathematicians held a banquet to entertain Pang Xuelin and his party.

After eating, there was naturally nothing to do, and everyone went back to their rooms to rest.

The International Congress of Mathematicians will not open until August 8, and mathematicians from all over the world will arrive in St. Petersburg on these two days.

Everyone rested in the hotel for a night, and the next morning, after eating the hotel's buffet breakfast, Pang Xuelin just returned to the room when the door was banged.

Pang Xuelin ran to open the door and saw Perelman and Shinichi Mochizuki standing at the door.

Shinichi Mochizuki was the first to speak: "Pang, Grigory is going home, do you want to go and have a look?" ”

"Okay, wait for me."

Pang Xuelin laughed.

Soon, he cleaned up and followed Perelman and Mochizuki down the stairs.

As soon as he walked to the door of the hotel, Pang Xuelin saw that Zuo Yiqiu and Ai Ai were walking hand in arm, talking intimately as they walked.

Pang Xuelin was a little curious, and he didn't know how these two girls looked at each other.

When Zuo Yiqiu followed Pang Xuelin, he rarely showed this state.

Most of the time she is more serious and a little heavy-minded.

When she was in Jiangcheng, although the relationship between her and Yao Bingxia and Qi Xin was not bad, it was far from being intimate.

On the contrary, when he was with Ai Ai, Pang Xuelin vaguely saw the deliberately suppressed nature of Zuo Yiqiu.

"Where are you going?"

Pang Xuelin said curiously.

Hearing Pang Xuelin's voice, both of them raised their heads.

Ai Ai took the lead and smiled: "Master, Sister Zuo and I are going to go out for a walk. ”

Zuo Yiqiu also asked, "Professor Pang, are you going to go out?" Do you want me to follow? ”

Pang Xuelin smiled and waved his hand: "It's okay, just have Zhou Chen with you." Take a day off today, you go out with Ai Ai, and don't come back too late. ”

"Okay."

Zuo Yiqiu nodded.

Ai Ai smiled and said, "Master, then let's go first." ”

As he spoke, he pulled Zuo Yiqiu and walked out of the hotel directly.

Pang Xuelin shook his head with a smile, and said to Perelman and Mochizuki on the side: "Let's go too." ”

The trio then boarded the convoy that was waiting at the door.

This time he went abroad, Pang Xuelin's security level was completely equipped in accordance with the specifications of high-level leaders, and even the bulletproof car he was riding in was airlifted from China.

Pang Xuelin didn't care, with his current ability, ordinary assassinations didn't pose a threat to him at all.

Soon, the car started up and drove towards the neighborhood where Perelman had previously lived.

Twenty minutes later, the convoy stopped near an old neighborhood.

The architectural style of this community has a strong Soviet era atmosphere, and there are not many pedestrians around, and occasionally people passing by will look at Pang Xuelin and his party curiously.

The infrastructure near the neighborhood is limited, and the cracked asphalt pavement, fallen leaves, and rusty bus stop signs look a little dilapidated.

"Grigory, is this where you grew up?"

Pang Xuelin was a little curious.

Perelman nodded, a hint of nostalgia on his face.

"Let's go inside."

Perelman said.

Pang Xuelin nodded, and said to Zhou Chen on the side: "You stay outside, and I will go with Professor Grigory and Professor Mochizuki Shinichi." ”

"But Professor Pang ......"

Zhou Chen hesitated.

Pang Xuelin said with a smile: "Don't worry, our itinerary was reported to the Russian authorities yesterday, and the safety here must have been screened, and aren't there still your Russian counterparts around?" ”

Seeing Pang Xuelin's resolute attitude, Zhou Chen could only nod helplessly.

Pang Xuelin, along with Perelman and Mochizuki, entered this dilapidated neighborhood together.

To Pang Xuelin's surprise, Perelman did not take them home directly, but first went to a small grocery store hidden in the corner.

The owner, a bearded old man with a red nose, was a little surprised and surprised by Perelman's arrival.

"Grigory, I haven't seen you for a long time, I heard that you went to China, how are you doing lately?"

Perelman nodded and said, "I'm fine, old Wade, bring me a pack of black coffee, three pieces of rye bread, three red sausages, oh yes, and a small bottle of vodka." ”

"Okay, it's 725 rubles."

Perelman touched his pocket, a look of embarrassment on his face.

Pang Xuelin and Shinichi Mochizuki on the side also looked at each other, and they also didn't bring money.

Old Wade seemed to see their predicament, and said with a smile: "Grigory, you take the things first, and I will treat you great mathematicians to eat." ”

Pang Xuelin was curious: "Do you know us?" ”

Old Wade pointed to the TV in the corner and said with a smile: "Why don't you know?" You are Professor Pang Xuelin, the famous inventor of the lithium-air battery. The professor next to you, who is supposed to be Shinichi Mochizuki from Japan, is reported on TV. ”

Pang Xuelin laughed and said, "Mr. Wade, thank you very much." ”

"Oh, by the way, drink vodka, you don't have a cup, do you? I'll give you three more cups. ”

Old Wade took out three more small wine glasses and handed them to Pang Xuelin.

Pang Xuelin took it.

Subsequently, Pang Xuelin and Mochizuki Shinto's food followed Perelman to the bottom of an apartment.

When he was still more than 100 meters away from the apartment building, Perelman suddenly stopped and looked ahead in a daze.

"What's wrong with Grigory?"

Shinichi Mochizuki said curiously.

Perelman didn't speak, Pang Xuelin and Mochizuki Shinichi followed Perelman's gaze, and saw a woman in her forties wandering at the entrance of the stairs downstairs in the apartment.

"Grigory, do you know the woman? Is it your lover? ”

Shinichi Mochizuki on the side said curiously.

Perelman didn't answer, but Pang Xuelin helped Perelman explain: "It shouldn't be, I think it may be Grigory's sister." ”

Pang Xuelin had previously investigated Perelman's information and knew a lot about his life.

Perelman was born on June 13, 1966, in St. Petersburg, Soviet Union, to a Jewish family where his father was an electronics engineer and his mother was an elementary school math teacher.

Although his ordinary parents could not provide him with superior material living conditions, they gave him a bright and studious mind.

When Perelman was four years old, he became interested in numbers and began to chew on elementary school math textbooks.

At the age of six, Perelman entered the elementary school where his mother taught.

At that time, he was already able to easily do three-digit addition, subtraction, multiplication and division in his head, while his classmates had just learned to do pen-calculating within two digits.

In 1982, Perelman enrolled in St. Petersburg Secondary School No. 239, a school that teaches mathematics and physics.

Just three months into school, he participated in the International Mathematical Olympiad and won a gold medal.

At the time, the sixteen-year-old teenage genius received the highest score ever——— out of 42.

A month after winning the award, the math prodigy received an invitation from a university in the United States to offer him a generous scholarship. However, he declined the invitation to study in the United States.

After graduating from secondary school, Perelman entered the Faculty of Mathematics of St. Petersburg University without exams.

In his sophomore year of college, he chose the most complex field of study in mathematics ——— differential geometry.

His classmates unanimously described him as smart as an alien and proficient in his major.

But he was careless about his appearance, often carrying a broken bag full of books, wearing a worn out garment, and not cutting his long hair.

He doesn't smoke or drink, and for a few years in college, he didn't even have many friends except for math.

In 1987, Perelman was admitted to the Sjacklov Institute of Mathematics of the USSR Academy of Sciences, where he remained after receiving his doctorate in 1989.

On weekends, he would go home to tutor his sister Elena in middle school, and in the evenings he would play the violin, his sister would sing and dance, and his parents would be their audience, and the family of four enjoyed themselves.

Later, his sister also became a mathematician, working in biostatistics at the prestigious Karolinska Institutet in Sweden, which was not unrelated to Perelman's influence.

However, with the political changes in the Soviet Union, the Perelman family also underwent major changes.

After the collapse of the Soviet Union, many Jews living in the Soviet Union emigrated to Israel.

At the end of 1991, Perelman's father and sister joined the migrants, but his mother was adamant about not leaving Russia, and the two eventually parted ways.

This incident hit Perelman hard.

Since then he has closed himself off and is determined to never leave his mother.

Perelman's personality will become so withdrawn and unsociable, and the departure of her father and sister should have a lot to do with it.

In the past two years, after coming to Jiangcheng University. Perelman's personality has only become a little more cheerful.

"Professor Pang, Xinyi, I may have some personal matters that need to be dealt with, you can wait for me here."

Pang Xuelin nodded and said, "You go." ”

Perelman stepped forward and said a few words to the woman, and soon the two entered the hallway.

"Pang, what are we going to do next?"

Mochizuki Shimo.

Pang Xuelin laughed, pointed to the stone table and chair in the small garden not far away, and said, "Let's go sit there and have a little wine, and wait for Grigory to come out." ”

"Okay."

Shinichi Mochizuki said.

Then, the two of them went straight to the stone table and sat down, placing the food they had just bought on it.

Pang Xuelin directly tore the film of the red sausage with his fingernails, opened the vodka again, and poured a glass for himself and Mochizuki Shinichi.

It's August in St. Petersburg, and the average temperature is only about 20 degrees, neither cold nor hot, and it's very comfortable.

The two of them chatted while drinking wine on red sausages.

Vodka is an ultra-high-concentration liquor, which is basically an alcoholic taste, and does not have the mellow aroma of domestic liquor.

Mochizuki Shinichi couldn't stand it after two sips, but it was Pang Xuelin, who had red sausages while drinking, which was delicious.

He is basically not a picky eater and eats whatever he wants, except, of course, potatoes.

The Martian World has eaten potatoes for seven or eight years in a row, and that taste is still unforgettable.

After about two hours, Perelman and the woman finally came out of the house and came to Pang Xuelin and Mochizuki Shinichi.

"Professor Pang, let me introduce you, this is my sister Elena."

"Hello, Ms. Elena."

Pang Xuelin and Shinichi Mochizuki shook hands with Yelena respectively.

Elena smiled and said, "Professor Pang, Professor Shinichi, hello, thank you two for taking care of my brother during this time. ”

Pang Xuelin smiled and did not speak.

At this point, Elena turned her gaze to Perelman.

Perelman pondered for a moment and said, "Professor Pang, after the International Congress of Mathematicians, I would like to ask you for a leave. ”

"What's wrong?"

Pang Xuelin was slightly stunned, and said with some curiosity.

"My father died, and I discussed with my sister about bringing his ashes from Israel back to St. Petersburg to be buried with my mother," Perelman said. ”

Pang Xuelin said: "No problem, just say if you have any help then." ”

A faint smile appeared on Perelman's face and he nodded.

At this time, Irina said: "Grigory, then I won't bother you for now, if there is anything to call, I will be in St. Petersburg during this time, and after the International Congress of Mathematicians is over, I will call you, and then we will go to Israel together......"

Perelman nodded and said no more.

After Yelena left, Pang Xuelin and Shinichi Mochizuki went to Perelman's house to sit for a while.

Perelman's home is a two-bedroom apartment with only two rooms, one of which was converted into a study by Perelman, and it has not been inhabited for more than a year, except for a little more dust, the overall house is quite tidy.

Among them, Pang Xuelin was most impressed by the bookshelves in the study, from floor to ceiling, densely packed with various books and manuscripts, full of various formulas.

Pang Xuelin imagined the scene more than ten years ago, when Perelman proved Poincaré's conjecture in such an environment, and had a new understanding of this guy.

Most of the outside world's evaluation of Perelman is eccentric, withdrawn and autistic, and indifferent to fame and fortune.

When Perelman arrived in the United States in 1993 as a visiting scholar, he solved several mathematical problems, including the famous "soul conjecture".

His outstanding results soon attracted the attention of the American mathematical community.

A number of famous universities such as the University of California, Stanford University, Massachusetts Institute of Technology, and Princeton University hired him to teach with high salaries, but he declined.

A year later, he returned to work at the Sjacklov Institute of Mathematics in St. Petersburg.

For his achievements in mathematics, the European Mathematical Society awarded him the "Outstanding Mathematician Award" in 1996, but he declined.

In 2002 and 2003, Perelman posted three papers on his website, successfully solving the Poincaré conjecture, one of the seven major problems in mathematics.

This shocked the entire mathematical community, and in 2004 the Sjacklov Institute of Mathematics recommended him to be elected a member of the Russian Academy of Sciences, which he also refused.

The following year, he resigned from the firm.

At the International Mathematical Congress held in Madrid, Spain, in August 2006, the International Mathematical Union (IMU) decided to award the Fields Medal to Perelman.

However, in the face of this great honor, he also chose to refuse.

In a sense, mathematics is what Perelman is all about, and he rejects anything that affects his research.

This is why after proving Poincaré's conjecture, he agreed to give presentations at Harvard, Caltech, Princeton and other universities in the United States, but did not have time to attend the award ceremony of the International Congress of Mathematicians.

Because for him, it's a complete waste of time.

Even the reason why Perelman was willing to accept his invitation to work at Jiangcheng University was more because of his Ponzi geometry than the environment that Jiangcheng University could provide him.

Of course, in the two years at Jiangcheng University, both the academic environment of the Ponzi Geometry Seminar and the living environment of Jiangcheng obviously satisfied Perelman. Otherwise, with Perelman's temperament, I am afraid that he would have returned to St. Petersburg long ago and lived his life of isolation again.

Moreover, Pang Xuelin can also faintly feel that in the past two years of life at Jiangcheng University, Perelman's attitude towards academics has also changed a lot.

Otherwise, he would not have accepted the invitation to this international congress of mathematicians at all.

……

The three stayed in Perelman's house until late in the evening before returning to the hotel.

As a result, Pang Xuelin just returned to his room, and it didn't take long for a bunch of old acquaintances to come to the door.

The leader is Shinichi Mochizuki's teacher, the big man Faltins from Germany.

In addition, there are old acquaintances such as Peter Schultz, Pierre Deligne, Yau Chengtong.

When these old acquaintances arrived, Pang Xuelin naturally wanted to meet them for a while, and Shinichi Mochizuki and Perelman were also pulled over.

In the evening, everyone had a small cold dinner in the conference room of the hotel.

While chatting, they discussed the proof paper on the Hodge conjecture that Perelman and Pang Xuelin jointly published not long ago.

Pang Xuelin also specially found Ai Ai, who had been hanging around outside for a day, and introduced him to these bigwigs.

This can be regarded as accumulating contacts for Ai Ai's future development in the academic world.

It wasn't until nine o'clock in the evening that the cold dinner was successfully over.