astronomy

Wanxiong Shi

Wanxiong Shi is a astronomy topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Wanxiong Shi rather than just read about it. In short: Wanxiong Shi (Chinese: 施皖雄; pinyin: Shī Wǎnxióng; Pe̍h-ōe-jī: Si Oán-hiông; 6 October 1963 - 30 September 2021) was a Chinese mathematician. He was known for his fundamental work in the theory of Ricci flow.

Key takeaways

Wanxiong Shi belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Wanxiong Shi to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Wanxiong Shi from memory before moving on to harder problems.

Reference excerpt

Wanxiong Shi (Chinese: 施皖雄; pinyin: Shī Wǎnxióng; Pe̍h-ōe-jī: Si Oán-hiông; 6 October 1963 - 30 September 2021) was a Chinese mathematician. He was known for his fundamental work in the theory of Ricci flow.

Education Shi was a native of Quanzhou, Fujian. In 1978, Shi graduated from Quanzhou No. 5 Middle School, and entered the University of Science and Technology of China. Shi earned his bachelor's degree in mathematics in 1982, then he went to the Institute of Mathematics of Chinese Academy of Sciences and obtained his master's degree in mathematics in 1985 under the guidance of Lu Qikeng (Chinese: 陆启铿) and Zhong Jiaqing (Chinese: 钟家庆). Then Shi was recruited by Shing-Tung Yau to study under him at the University of California, San Diego. In 1987, Shi followed Yau to Harvard University and obtained his Ph.D. there in 1990. Since Shi was stronger in geometric analysis than other Chinese students, having an impressive ability to carry out highly technical arguments, he was assigned by Yau to investigate Ricci flow in the challenging case of noncompact manifolds. Shi made significant breakthroughs and was highly regarded by researchers in the field. Richard Hamilton, the founder of Ricci flow theory, liked his work very much.

Academic career and later life Upon his graduation, several prominent universities were interested in offering him a faculty position. Hung-Hsi Wu (Chinese: 伍鸿熙) from the University of California, Berkeley asked Yau if Shi could come to Berkeley. Without seeking opinion from Yau, Shi applied to and got tenure track assistant professorship offers from the University of California, San Diego, where Richard Hamilton was working at, and Purdue University. Shi decided to join Purdue University. He published several important papers there, and was awarded three grants from the NSF in 1991, 1994 and 1997. However, Shi did not pass the tenure review in 1997, so he had to leave the university. (The principal investigator of the NSF grant of 1997 was changed because of this.) Yau believes that the failure was due to the faculty members not realising the importance of Ricci flow theory. Hamilton sent a belated reference letter to Purdue University in which he rebuked the decision, but to no avail. Shi then left academia and moved to Washington D.C., where he lived a frugal and secluded life in solitude, and had less and less contact with his friends. He turned down some offers from other universities. Yau and former classmates of Shi tried to persuade Shi and help him return to academia, but he rejected. Yau felt sorry for Shi's leaving academia, since among the four students of Yau who worked on Ricci flow, Shi had done the best work. Shi died from a sudden heart attack in the evening of September 30, 2021.

Work Shi initiated the study of Ricci flow theory on noncompact complete manifolds. He proved local derivative estimates for the Ricci flow, which are fundamental to many arguments of the theory, including Perelman's proof of the Poincaré conjecture using Ricci flow in 2002.

Publications Shi, Wan-Xiong (1989). "Complete noncompact three-manifolds with non-negative Ricci curvature". J. Differ. Geom. 29 (2): 353–360. doi:10.4310/jdg/1214442879. Shi, Wan-Xiong (1989). "Deforming the metric on complete Riemannian manifolds". J. Differ. Geom. 30 (1): 223–301. doi:10.4310/jdg/1214443292. Shi, Wan-Xiong (1989). "Ricci deformation of the metric on complete non-compact Riemannian manifolds". J. Differ. Geom. 30 (2): 303–394. doi:10.4310/jdg/1214443595. Shi, Wan-Xiong (1990). "Complete noncompact Kähler manifolds with positive holomorphic bisectional curvature". Bull. Am. Math. Soc. New Ser. 23 (2): 437–440. doi:10.1090/S0273-0979-1990-15954-3. Shi, Wanxiong and Yau, S. T. (1994). "Harmonic maps on complete noncompact Riemannian manifolds". A tribute to Ilya Bakelman. Proceedings of a conference, College Station, TX, USA, October 1993. College Station, TX: Texas A & M University. pp. 79–120. ISBN 0-9630728-2-X.{{cite conference}}: CS1 maint: multiple names: authors list (link) Shi, Wan-Xiong and Yau, S.-T. (1996). "A note on the total curvature of a Kähler manifold". Math. Res. Lett. 3 (1): 123–132. doi:10.4310/MRL.1996.v3.n1.a12.{{cite journal}}: CS1 maint: multiple names: authors list (link) Shi, Wan-Xiong (1997). "Ricci flow and the uniformization on complete noncompact Kähler manifolds". J. Differ. Geom. 45 (1): 94–220. doi:10.4310/jdg/1214459756. Shi, Wan-Xiong (1998). "A uniformization theorem for complete Kähler manifolds with positive holomorphic bisectional curvature". J. Geom. Anal. 8 (1): 117–142. doi:10.1007/BF02922111. S2CID 121610392.

References

External links Wan-Xiong Shi at the Mathematics Genealogy Project

Worked examples

Example 1 — a first encounter with Wanxiong Shi

Start with the simplest possible case. Write down what Wanxiong Shi claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In astronomy, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Wanxiong Shi before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Wanxiong Shi ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Wanxiong Shi

In research: Wanxiong Shi appears in astronomy research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Wanxiong Shi in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Wanxiong Shi is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1963 births, 2021 deaths, 20th-century Chinese mathematicians, so understanding it makes those chapters shorter.
In everyday life: Look for Wanxiong Shi outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Wanxiong Shi in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Wanxiong Shi means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Wanxiong Shi out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Wanxiong Shi in simple terms?

Why does Wanxiong Shi matter?

Because it connects several astronomy ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Wanxiong Shi?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Wanxiong Shi.