{"title":"多项式轨道中的算术级数","authors":"Mohammad Sadek, Mohamed Wafik, Tuğba Yesin","doi":"10.1142/s1793042124500970","DOIUrl":null,"url":null,"abstract":"<p>Let <span><math altimg=\"eq-00001.gif\" display=\"inline\"><mi>f</mi></math></span><span></span> be a polynomial with integer coefficients whose degree is at least 2. We consider the problem of covering the orbit <span><math altimg=\"eq-00002.gif\" display=\"inline\"><msub><mrow><mo>Orb</mo></mrow><mrow><mi>f</mi></mrow></msub><mo stretchy=\"false\">(</mo><mi>t</mi><mo stretchy=\"false\">)</mo><mo>=</mo><mo stretchy=\"false\">{</mo><mi>t</mi><mo>,</mo><mi>f</mi><mo stretchy=\"false\">(</mo><mi>t</mi><mo stretchy=\"false\">)</mo><mo>,</mo><mi>f</mi><mo stretchy=\"false\">(</mo><mi>f</mi><mo stretchy=\"false\">(</mo><mi>t</mi><mo stretchy=\"false\">)</mo><mo stretchy=\"false\">)</mo><mo>,</mo><mo>…</mo><mo stretchy=\"false\">}</mo></math></span><span></span>, where <span><math altimg=\"eq-00003.gif\" display=\"inline\"><mi>t</mi></math></span><span></span> is an integer, using arithmetic progressions each of which contains <span><math altimg=\"eq-00004.gif\" display=\"inline\"><mi>t</mi></math></span><span></span>. Fixing an integer <span><math altimg=\"eq-00005.gif\" display=\"inline\"><mi>k</mi><mo>≥</mo><mn>2</mn></math></span><span></span>, we prove that it is impossible to cover <span><math altimg=\"eq-00006.gif\" display=\"inline\"><msub><mrow><mo>Orb</mo></mrow><mrow><mi>f</mi></mrow></msub><mo stretchy=\"false\">(</mo><mi>t</mi><mo stretchy=\"false\">)</mo></math></span><span></span> using <span><math altimg=\"eq-00007.gif\" display=\"inline\"><mi>k</mi></math></span><span></span> such arithmetic progressions unless <span><math altimg=\"eq-00008.gif\" display=\"inline\"><msub><mrow><mo>Orb</mo></mrow><mrow><mi>f</mi></mrow></msub><mo stretchy=\"false\">(</mo><mi>t</mi><mo stretchy=\"false\">)</mo></math></span><span></span> is contained in one of these progressions. In fact, we show that the relative density of terms covered by <span><math altimg=\"eq-00009.gif\" display=\"inline\"><mi>k</mi></math></span><span></span> such arithmetic progressions in <span><math altimg=\"eq-00010.gif\" display=\"inline\"><msub><mrow><mo>Orb</mo></mrow><mrow><mi>f</mi></mrow></msub><mo stretchy=\"false\">(</mo><mi>t</mi><mo stretchy=\"false\">)</mo></math></span><span></span> is uniformly bounded from above by a bound that depends solely on <span><math altimg=\"eq-00011.gif\" display=\"inline\"><mi>k</mi></math></span><span></span>. In addition, the latter relative density can be made as close as desired to <span><math altimg=\"eq-00012.gif\" display=\"inline\"><mn>1</mn></math></span><span></span> by an appropriate choice of <span><math altimg=\"eq-00013.gif\" display=\"inline\"><mi>k</mi></math></span><span></span> arithmetic progressions containing <span><math altimg=\"eq-00014.gif\" display=\"inline\"><mi>t</mi></math></span><span></span> if <span><math altimg=\"eq-00015.gif\" display=\"inline\"><mi>k</mi></math></span><span></span> is allowed to be large enough.</p>","PeriodicalId":14293,"journal":{"name":"International Journal of Number Theory","volume":null,"pages":null},"PeriodicalIF":0.5000,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Arithmetic progressions in polynomial orbits\",\"authors\":\"Mohammad Sadek, Mohamed Wafik, Tuğba Yesin\",\"doi\":\"10.1142/s1793042124500970\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>Let <span><math altimg=\\\"eq-00001.gif\\\" display=\\\"inline\\\"><mi>f</mi></math></span><span></span> be a polynomial with integer coefficients whose degree is at least 2. We consider the problem of covering the orbit <span><math altimg=\\\"eq-00002.gif\\\" display=\\\"inline\\\"><msub><mrow><mo>Orb</mo></mrow><mrow><mi>f</mi></mrow></msub><mo stretchy=\\\"false\\\">(</mo><mi>t</mi><mo stretchy=\\\"false\\\">)</mo><mo>=</mo><mo stretchy=\\\"false\\\">{</mo><mi>t</mi><mo>,</mo><mi>f</mi><mo stretchy=\\\"false\\\">(</mo><mi>t</mi><mo stretchy=\\\"false\\\">)</mo><mo>,</mo><mi>f</mi><mo stretchy=\\\"false\\\">(</mo><mi>f</mi><mo stretchy=\\\"false\\\">(</mo><mi>t</mi><mo stretchy=\\\"false\\\">)</mo><mo stretchy=\\\"false\\\">)</mo><mo>,</mo><mo>…</mo><mo stretchy=\\\"false\\\">}</mo></math></span><span></span>, where <span><math altimg=\\\"eq-00003.gif\\\" display=\\\"inline\\\"><mi>t</mi></math></span><span></span> is an integer, using arithmetic progressions each of which contains <span><math altimg=\\\"eq-00004.gif\\\" display=\\\"inline\\\"><mi>t</mi></math></span><span></span>. Fixing an integer <span><math altimg=\\\"eq-00005.gif\\\" display=\\\"inline\\\"><mi>k</mi><mo>≥</mo><mn>2</mn></math></span><span></span>, we prove that it is impossible to cover <span><math altimg=\\\"eq-00006.gif\\\" display=\\\"inline\\\"><msub><mrow><mo>Orb</mo></mrow><mrow><mi>f</mi></mrow></msub><mo stretchy=\\\"false\\\">(</mo><mi>t</mi><mo stretchy=\\\"false\\\">)</mo></math></span><span></span> using <span><math altimg=\\\"eq-00007.gif\\\" display=\\\"inline\\\"><mi>k</mi></math></span><span></span> such arithmetic progressions unless <span><math altimg=\\\"eq-00008.gif\\\" display=\\\"inline\\\"><msub><mrow><mo>Orb</mo></mrow><mrow><mi>f</mi></mrow></msub><mo stretchy=\\\"false\\\">(</mo><mi>t</mi><mo stretchy=\\\"false\\\">)</mo></math></span><span></span> is contained in one of these progressions. In fact, we show that the relative density of terms covered by <span><math altimg=\\\"eq-00009.gif\\\" display=\\\"inline\\\"><mi>k</mi></math></span><span></span> such arithmetic progressions in <span><math altimg=\\\"eq-00010.gif\\\" display=\\\"inline\\\"><msub><mrow><mo>Orb</mo></mrow><mrow><mi>f</mi></mrow></msub><mo stretchy=\\\"false\\\">(</mo><mi>t</mi><mo stretchy=\\\"false\\\">)</mo></math></span><span></span> is uniformly bounded from above by a bound that depends solely on <span><math altimg=\\\"eq-00011.gif\\\" display=\\\"inline\\\"><mi>k</mi></math></span><span></span>. In addition, the latter relative density can be made as close as desired to <span><math altimg=\\\"eq-00012.gif\\\" display=\\\"inline\\\"><mn>1</mn></math></span><span></span> by an appropriate choice of <span><math altimg=\\\"eq-00013.gif\\\" display=\\\"inline\\\"><mi>k</mi></math></span><span></span> arithmetic progressions containing <span><math altimg=\\\"eq-00014.gif\\\" display=\\\"inline\\\"><mi>t</mi></math></span><span></span> if <span><math altimg=\\\"eq-00015.gif\\\" display=\\\"inline\\\"><mi>k</mi></math></span><span></span> is allowed to be large enough.</p>\",\"PeriodicalId\":14293,\"journal\":{\"name\":\"International Journal of Number Theory\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.5000,\"publicationDate\":\"2024-05-29\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"International Journal of Number Theory\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://doi.org/10.1142/s1793042124500970\",\"RegionNum\":3,\"RegionCategory\":\"数学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"MATHEMATICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Number Theory","FirstCategoryId":"100","ListUrlMain":"https://doi.org/10.1142/s1793042124500970","RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 0
摘要
我们考虑的问题是用算术级数覆盖轨道 Orbf(t)={t,f(t),f(f(t)),...},其中 t 是整数,而每个算术级数都包含 t。固定整数 k≥2,我们证明除非 Orbf(t) 包含在其中一个算术级数中,否则不可能用 k 个这样的算术级数覆盖 Orbf(t)。事实上,我们证明了在 Orbf(t) 中,由 k 个这样的算术级数所覆盖的项的相对密度是由一个完全取决于 k 的约束从上均匀限定的。
Let be a polynomial with integer coefficients whose degree is at least 2. We consider the problem of covering the orbit , where is an integer, using arithmetic progressions each of which contains . Fixing an integer , we prove that it is impossible to cover using such arithmetic progressions unless is contained in one of these progressions. In fact, we show that the relative density of terms covered by such arithmetic progressions in is uniformly bounded from above by a bound that depends solely on . In addition, the latter relative density can be made as close as desired to by an appropriate choice of arithmetic progressions containing if is allowed to be large enough.
期刊介绍:
This journal publishes original research papers and review articles on all areas of Number Theory, including elementary number theory, analytic number theory, algebraic number theory, arithmetic algebraic geometry, geometry of numbers, diophantine equations, diophantine approximation, transcendental number theory, probabilistic number theory, modular forms, multiplicative number theory, additive number theory, partitions, and computational number theory.