Algebraic Number Starscapes
Algebraic Number Starscapes
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代数数星空
DOI:
10.1080/10586458.2022.2102094
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发表时间:
2022
影响因子:
0.5
通讯作者:
Trettel, Steve
中科院分区:
文献类型:
--
作者:
Harriss, Edmund;Stange, Katherine E.;Trettel, Steve
We study the geometry of algebraic numbers in the complex plane, and their Diophantine approximation, aided by extensive computer visualization. Motivated by the resulting images, which we have calledalgebraic starscapes, we describe the geometry of the map from the coefficient space of polynomials to the root space, focusing on the quadratic and cubic cases. The geometry describes and explains the notable features of the illustrations, and motivates a geometric-minded recasting of fundamental results in the Diophantine approximation of the complex plane. Meanwhile, the images provide a case-study in the symbiosis of illustration and research, and an entry-point to geometry and number theory for a wider audience. In particular, the paper is written to provide an accessible introduction to the study of homogeneous geometry and Diophantine approximation. We investigate the homogeneous geometry of root and coefficient spaces under the naturalaction. Hyperbolic geometry and the discriminant play an important role in low degree. In particular, we rediscover the quadratic and cubic root formulas as isometries ofand its unit tangent bundle, respectively. Utilizing this geometry, we determine when the map sending certain families of polynomials to their complex roots (our starscape images) are embeddings. We reconsider the fundamental questions of the Diophantine approximation of complex numbers by algebraic numbers of bounded degree, from the geometric perspective developed. In the quadratic case (approximation by quadratic irrationals), we consider approximation in terms ofhyperbolicdistance between roots in the complex plane and thediscriminantas a measure of arithmetic height on a polynomial. In particular, we determine the supremum on the exponentkfor which an algebraic targetαhas infinitely many approximationsβwhose hyperbolic distance fromαdoes not exceed. It turns out to fall into two cases, depending on whetherαlies on the image of a plane of rational slope in coefficient space (arational geodesic). The result comes as an application of Schmidt’s subspace theorem. Our results recover the quadratic case of results of Bugeaud and Evertse, and give some geometric explanation for the dichotomy they discovered. Our statements go a little further in distinguishing approximability in terms of whether the target or approximations lie on rational geodesics. The paper comes with accompanying software, and finishes with a wide variety of open problems.
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影响因子:
0.8
作者:
Matthew Bates
通讯作者:
Matthew Bates
DOI:
10.1007/s11139-016-9820-2
发表时间:
2017
期刊:
The Ramanujan Journal
影响因子:
--
作者:
Nadir Murru
通讯作者:
Nadir Murru
影响因子:
0.7
作者:
J. Wolfskill
通讯作者:
J. Wolfskill
影响因子:
0.7
作者:
H. Davenport;W. Schmidt
通讯作者:
W. Schmidt
DOI:
10.1080/00029890.2001.11919824
发表时间:
2001
期刊:
The American Mathematical Monthly
影响因子:
--
作者:
P. Borwein;Loki Jörgenson
通讯作者:
Loki Jörgenson