Chapter 329 Unexpected Visitors and Hodge’s Theory
Leave Longjiang and return to the capital.
It was as if these two girls were beginning to take acting classes at the Beijing Film and Television Department, focusing on releasing their natural instincts with one hand.
The rivalry and jealousy that was originally suppressed in front of the elders can no longer be suppressed at this time, not to mention that Qiu Jing was so close when talking to Xu Qingshan just now, and A completely different type from the two of them. Even though the two of them have nothing at all, they still have an inexplicable sense of crisis.
Fortunately, Xu Qingshan and Wang Chuan can take refuge.
A young man's copper-stove hotpot dinner passed by like this, lively and good.
The next day, it was only two days before the start of school at Beijing University.
Students are starting to return to school one after another.
Tong Tong needs to go to the competition and training team to register and report and receive the new study materials. Jiang Huanxi needs to go to the dormitory in advance to clean and tidy up. She will officially move out of the dormitory this semester. Lived.
I came early and just went to the hospital office to submit the application and go through the procedures.
If this is an ordinary student in an ordinary school or college, the counselor will not let him go, and he can only rely on illegal operations.
But the relationship between Jiang Huanxi and Xu Qingshan is not a secret.
Students at Yuanpei College have always had more freedom. When they found out that the place where Jiang Huanxi moved was actually Yandongyuan, the counselor sister, who was actually a few years older than Jiang Huanxi, took care of her. Jiang Huanxi was pulled into a small dark room and explained a bunch of safety precautions in a serious voice before letting Jiang Huanxi leave with a red face.
Looking at Jiang Huanxi's back quickly leaving the hospital office in small steps, the counselor sister couldn't help but let out a long sigh and said with emotion.
"What kind of world is this? I am a young girl telling these safety concepts to a little girl who has already tasted meat? Will she think I am redundant?"
Everyone is busy with their own affairs.
Xu Qingshan also took a look at the office of the Institute of Mathematics Research.
Xiao Xue and Xiao Wang have been sitting in the office for a long time. Judging from the look of their desktops, they have been in school for at least a week or two.
Also, doctoral students start school earlier than undergraduate students.
Professors generally live near the school, and they do not have a specific start time, because they do not have holidays at all. They take students and assistants to continue doing scientific research and experiments during summer and winter vacations. A commonplace thing.
Maybe a bug like Qingshan's special case can be stuck.
He has the function of a professor, but at the same time his identity card is that of an undergraduate student.
"Why, aren't you having a happy Spring Festival?"
As soon as Xu Qingshan entered the office, he saw the two older girls with sad faces. Xue Xuequing saw Xu Qingshan, who was the first Standing up, Hun was still sitting at the table. Her originally yellow hair had now turned into peach pink, but with her dry ends and messy chicken coop, it was obvious that she had not been going well recently.
Wang Kaizui on the other side moved first, but he couldn't react.
First she called "teacher", and after three seconds of speaking, she slowly got up, grinding the chair with her on the ground.
“The Spring Festival is okay, it’s our thesis. I want to do the questions about the direction of Diophantus, but I have no clue about several questions in succession. Now I am reading the 23 questions in Hilbert 1900. Question 10, but I found that I did not understand Matiajecevich’s paper.”
“ I am happy during the Spring Festival. But what is worse for me than Xueqing is that I am reproducing your whole process, teacher. But I am stuck. There are several steps that I found that I have not fully understood, but I dare not call you during the holiday. ”
Looking at the two older girls complaining in front of him, Xu Qingshan shook his head helplessly.
It was just a matter of a phone call. No matter how troublesome it was, we still ended up splitting up.
"It's all easy to say, Xiao Xue. What you are talking about is, 'A polynomial equation has any number of unknowns. Can it be determined through a feasible evolution and in a finite number of operations whether this equation has an integer solution?' The tenth question?" In his doctoral thesis, Matiajecevich proved that there is no general algorithm that can solve all Diophantine equations, right? ”< br>
“Yes, that’s it. I read a lot of classic documents and research history. I searched everything I could find. I also looked at the Turing machine theory given by Turing, and Gödel’s. "
"Don't look forward, look back."
Xu Qingshan stretched out his hand to interrupt Xiao Xue's performance and said.
“Go and read Jones’ paper in the Journal of Symbolic Logic in 1982, which details the argument that there is no algorithm that can be used to determine whether any integer polynomial equation with 9 unknown numbers has a natural number solution. Details of the tenth question Detailed analysis, if you still have questions after reading that article, you can read Sun Zhiwei's 1989 article "Necessary and Sufficient Conditions for Two Linear Diophantine Equations to Have Public Solutions" in the Journal of Jinling University and the 1991 article in Chinese Science A "The Reduction of Unknown Numbers in the Representation of Diophantus" edited by me, come back to me if you still don't understand. ”
After Xu Qingshan finished speaking, he saw Xue Xuequing, who felt a little guilty, and reached out to knock her on the head.
“Also, sometimes don’t just think about looking for some problems in foreign journals. Sometimes there are good insights in China. Although there is indeed a gap in terms of proportion, but when doing scientific research, Since you are interested in things, you must be comprehensive enough and don’t say there is no way out before you have tried your best. Remember?”
“Remember”
Xue Xuequing? He sat down aggrievedly and honestly looked for the paper Xu Qingshan mentioned.
Over there, Wang Wei was slow to react.
She immediately sat down and looked at her computer screen intently, even though it was currently showing Spider Solitaire.
“It’s Xiao Wang’s turn next.”
Xu Qingshan looked at Wang Wei.
"Old teacher, I, I, I don't need to ask, I'll take another look and maybe I'll understand."
No wonder Wang Wei didn't even make a phone call during the Chinese New Year. Dare to fight.
Xu Qingshan thought that he didn't seem to have taught her a lesson? What part of it made your image so fierce? Can a baby stop crying and a doctor stop asking questions?
“Stop talking nonsense, show me what you don’t understand? The project I worked on ended up being that even my team members didn’t understand it. If someone asks you and knocks you down, what’s the point? Didn’t you lose my face?”
Xu Qingshan lightly patted Wang Wei on the shoulder and said jokingly.
As a result, Wang Wei suddenly trembled all over and his voice was filled with tears.
“Teacher, I really didn’t work hard, I am, I am.”
"Okay, okay, I didn't say you don't work hard. Show me the problem first and I'll explain it to you briefly. Just kidding, you are already much better than others."
Xu Qingshan took it back Hand, helplessly comforted.
Fortunately, Wang Wei's questions are indeed a bit more tricky. There are indeed some small steps in some places. Jiang Huanxi has the basics, but he still doesn't grasp the deep enough in some places. Without Wang Wei's review, Xu Qingshan might really be Didn't care.
After explaining his thoughts, Wang Wei seemed to have become much clearer. "Then you should work on these questions next. When the time comes, unify them and publish a work. It should be easy to publish a work in the SCI area. See if you can vote for new progress. After all, this is nothing until you win the prize. It’s a popular field, I recommend it to you.”
Xu Qingshan patted Wang Kai on the shoulder again, and was about to go back to his seat to sort out the ideas for his next research.
The hot-eyed Xue Xuequing threw away her slight grievance and panic in the blink of an eye, raising her hands and shouting like a primary school student.
“Teacher, I want it too, I want it too!”
“You show me the paper first, and after reading it I will find you a topic in the same field as Diophantus for you to study. Take a look and follow me when the time comes."
Xu Qingshan simply ignored the lively girl who was trying her best to be cute and sat back in her seat.
Xue Xuequing could only sit back with a pout and continue to look up information, but she couldn't hide the joy on her face. Although Director Xu drew the cake, could Director Xu's cake be comparable to other people's cakes?
This is real money and silver cake! The kind that can eat vigorously until full!
Xu Qingshan found a piece of paper, thought about it, and simply wrote down the basic idea he just talked to Xue Xuequing on it.
He is able to master so many papers related to Diophantus, and his ability to talk about the development history of various issues in the field of Diophantus is not something he was born with.
My friend is just reborn, not caught in the rain, and will not become a god-like child who knows everything.
But after finishing the work before, Xu Qingshan consciously wanted to see how Diophantus was related, because in the process of proving the twin prime conjecture, Xu Qingshan used similar ideas many times to find a way.
[Duffin-Schaeffer Conjecture]
Xu Qingshan wrote a line of black words, and then wrote [Dirichlet’s Theorem].
He quickly organized his thoughts.
In the field of mathematics, especially in the field of pure numbers, there are many various important conjectures. Many conjectures appear to be quite simple at first glance, but they have not been solved for a long time.
Just like the guess he is holding now, which is not famous at first glance, it is actually a pinyin-vowel level existence in the field of Diophantine approximation.
The pen in Xu Qingshan’s hand did not stop, but he clarified the entire issue.
First assume a continuous function. The question is whether there are infinitely many existing rational numbers p/q (q>0, (p, q) = 1) for a real number x such that x minus p/q is absolutely The absolute value of the value is less than the continuous function taking q.
When the continuous function of q is equal to the -2 power of q, it is actually Dirichlet's theorem: for any real number x, there are infinitely many rational numbers that satisfy the inequality.
It's just that.
Xu Qingshan's thinking is obviously more exciting.
He did not stop at the Duffin-Schaeffer conjecture, but after writing densely, he opened another page and wrote the [Wirsing-Schmidt conjecture].
Just when he forgot that he had to clean up the table and materials, he started to enter that mysterious and mysterious state as soon as his butt stuck to this long-lost but familiar engineering chair.
The knock on the door of the office attracted the attention of the three people in the office.
Xu Qingshan raised his head in surprise.
At this point, Tong Tong and Jiang Huanxi probably haven't finished their work yet, so it's impossible for them to come here.
Even if you come to the office, given their familiarity, do you still need to knock on the door?
But when he looked up, Xu Qingshan saw an old friend who was as familiar as the ergonomic chair under his butt.
Actually, it’s not necessarily true that we are old friends, we just had some in-depth conversations.
Looking at the handsome-looking senior brother Liu Ruochuan in front of him, who was wearing a decent brown suit, Xu Qingshan blinked. His first words were not to welcome him and greet him, but< br>
"Brother, is it really not cold outside when you are dressed like this?"
Liu Ruochuan, who was holding a briefcase in one hand and a box of exquisite gift boxes in the other, was startled, but his smile did not diminish and he shook his head. He shook his head, walked in, put down his things on Xu Qingshan's desk very familiarly, and pulled a chair from the side to sit on.
"What's so cold? I just came back from France, but France is really warm, much warmer than the capital."
"Warm? Really? Doesn't Paris have a Mediterranean climate? ? Isn’t it colder when it rains in winter? ?”
Xu Qingshan moved the exquisite gift box brought by Liu Ruochuan. It was full of foreign languages. He had never learned it. It looked like English, but it seemed to be quite different. The composition and word order of the letters look like French.
When Liu Ruochuan heard Xu Qingshan's question, his reaction was even greater than before. He looked at Xu Qingshan in disbelief.
"Huh?! Didn't you get perfect marks in the college entrance examination? Isn't this in the geography book? Why don't you even know this? Paris has a temperate maritime climate, in northern France."
Xu Qingshan blinked, lowered his head and opened the gift.
“I am the top scorer in science, with perfect marks in science, but not in liberal arts. I will finish the geography exam when I am a sophomore in high school. I haven’t started to work hard in my sophomore year of high school yet.”
“Like this Ah, I thought you were really good at the decathlon. Hey, hey, I didn’t even say I was going to give it to you. You guys are so shameless and just took it apart.”
Liu Ruochuan took off his suit jacket.
It feels even warmer when you enter the house. The heating in the house is not installed in vain.
"They were all brought to my table. They were not given to me, but they were given to me. But senior brother, you really came without even saying hello. What's wrong? Do you love me so much? From now on. Come and see me first when you come back from France?”
Xu Qingshan looked at the contents of the gift box. It was a set of enamel porcelain that looked very exquisite, but why did it look more and more like it was made in China? What about?
Xu Qingshan took the gift box and looked over it, hoping to find some clues.
"I thought too much. I went to see the teacher first. The teacher told me that it would be no problem to come to you for this matter, so I came to see you."
Hearing this, Xu Qingshan put down the porcelain in his hand. He returned to the gift box and closed the lid of the gift box three times.
"Go out, turn left, walk slowly, don't send it off."
He continued to read the manuscript he had just written.
"Hey, Qingshan, don't be so arrogant. I brought this here especially for you. I think you young people who fall in love will definitely like this kind of thing. How good is it to coax girls?"
Liu Ruochuan raised his eyebrows and looked at Xu Qingshan with a flattering expression.
“Let’s talk about what we want to do first.”
Xu Qingshan’s face was expressionless.
“Hodge theory, I have recently been working on applications related to p-advanced Hodge theory. Isn’t this a disadvantage of being someone with strong computing power, good ideas, and awesome people? Look, isn’t this just for you? Did I tailor it?”
(End of this chapter)