The algebraic numbers definable in various exponential fields

Type: Article
Publication Date: 2012-04-02
Citations: 7
DOI: https://doi.org/10.1017/s1474748012000047

Abstract

Abstract We prove the following theorems. Theorem 1: for any E-field with cyclic kernel, in particular ℂ or the Zilber fields, all real abelian algebraic numbers are pointwise definable. Theorem 2: for the Zilber fields, the only pointwise definable algebraic numbers are the real abelian numbers.

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  • Journal of the Institute of Mathematics of Jussieu
  • arXiv (Cornell University)
  • DataCite API

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We study solutions of exponential polynomials over the complex field. Assuming Schanuel's Conjecture we prove that certain polynomials of the form \[ p(z, e^z, e^{e^z}, e^{e^{e^{z}}}) = 0 \] have … We study solutions of exponential polynomials over the complex field. Assuming Schanuel's Conjecture we prove that certain polynomials of the form \[ p(z, e^z, e^{e^z}, e^{e^{e^{z}}}) = 0 \] have generic solutions in $\mathbb C$.
The algebra of exponential fields and their extensions is developed. The focus is on ELA-fields, which are algebraically closed with a surjective exponential map. In this context, finitely presented extensions … The algebra of exponential fields and their extensions is developed. The focus is on ELA-fields, which are algebraically closed with a surjective exponential map. In this context, finitely presented extensions are defined, it is shown that finitely generated strong extensions are finitely presented, and these extensions are classified. An algebraic construction is given of Zilber's pseudo-exponential fields. As applications of the general results and methods of the paper, it is shown that Zilber's fields are not model-complete, answering a question of Macintyre, and a precise statement is given explaining how Schanuel's conjecture answers all transcendence questions about exponentials and logarithms. Connections with the Kontsevich-Zagier, Grothendieck, and Andr\'e transcendence conjectures on periods are discussed, and finally some open problems are suggested.
We continue the research programme of comparing the complex exponential with Zilberś exponential. For the latter, we prove, using diophantine geometry, various properties about zero sets of exponential functions, proved … We continue the research programme of comparing the complex exponential with Zilberś exponential. For the latter, we prove, using diophantine geometry, various properties about zero sets of exponential functions, proved for $\mathbb{C}$ using analytic function theory, for example, the Identity Theorem.
In this paper we prove Shapiro’s 1958 Conjecture on exponential polynomials, assuming Schanuel’s Conjecture. In this paper we prove Shapiro’s 1958 Conjecture on exponential polynomials, assuming Schanuel’s Conjecture.
In this paper, we briefly outline the definition of Zilber field, which is a structure analogue to the complex field with the exponential function. An open conjecture, including Schanuel’s Conjecture, … In this paper, we briefly outline the definition of Zilber field, which is a structure analogue to the complex field with the exponential function. An open conjecture, including Schanuel’s Conjecture, is whether the complex field is itself one of these structure. In view of this conjecture, a natural question raised by Zilber, Kirby, Macintyre and others is whether they have an automorphism of order two akin to complex conjugation. We announce, without proof, the positive answer: for cardinality up to the continuum there exists an involution of the field commuting with the exponential function. Moreover, in the case of cardinality of the continuum, the automorphism can be taken such that its fixed field is exactly ℝ , and the kernel of the exponential function is 2\pi i \mathbb Z .
We show that in the ring generated by the integers and the functions $x, \ \sin x^{n}$ and $\sin (x\cdot \sin x^{n})$ $(n=1,2,\ldots )$ defined on $\mathbf {R}$ it is … We show that in the ring generated by the integers and the functions $x, \ \sin x^{n}$ and $\sin (x\cdot \sin x^{n})$ $(n=1,2,\ldots )$ defined on $\mathbf {R}$ it is undecidable whether or not a function has a positive value or has a root. We also prove that the existential theory of the exponential field $\mathbf {C}$ is undecidable.
I give an algebraic proof that the exponential algebraic closure operator in an exponential field is always a pregeometry, and show that its dimension function satisfies a weak Schanuel property.A … I give an algebraic proof that the exponential algebraic closure operator in an exponential field is always a pregeometry, and show that its dimension function satisfies a weak Schanuel property.A corollary is that there are at most countably many essential counterexamples to Schanuel's conjecture.
When studying the model theory of the first observation is that the integers can be defined as Since ∂ exp is subject to all of Gödel's phenomena, this is often … When studying the model theory of the first observation is that the integers can be defined as Since ∂ exp is subject to all of Gödel's phenomena, this is often also the last observation. After Wilkie proved that ℝ exp is model complete, one could ask the same question for ∂ exp , but the answer is negative. P roposition 1.1. ∂ exp is not model complete P roof . If ∂ exp is model complete, then every definable set is a projection of a closed set. Since ∂ is locally compact, every definable set is F σ . The same is true for the complement, so every definable set is also G δ . But, since ℤ is definable, ℚ is definable and a standard corollary of the Baire Category Theorem tells us that ℚ is not G δ . Still, there are several interesting open questions about ∂ exp . • Is ℝ definable in ∂ exp ? • (quasiminimality) Is every definable set countable or co-countable? (Note that this is true in the structure (∂, ℤ, +, ·) where we add a predicate for ℤ). • (Mycielski) Is there an automorphism of ∂ exp other than the identity and complex conjugation? 1 A positive answer to the first question would tell us that ∂ exp is essentially second order arithmetic, while a positive answer to the second would say that integers are really the only obstruction to a reasonable theory of definable sets. A fascinating, novel approach to ∂ exp is provided by Zilber's [6] pseudoexponentiation. Let L be the language {+, · E , 0, 1}.
We show that Conway's field of surreal numbers with its natural exponential function has the same elementary properties as the exponential field of real numbers. We obtain ordinal bounds on … We show that Conway's field of surreal numbers with its natural exponential function has the same elementary properties as the exponential field of real numbers. We obtain ordinal bounds on the length of products, reciprocals, exponentials and logarithms
We show that Zilber's conjecture that complex exponentiation is isomorphic to his pseudo-exponentiation follows from the a priori simpler conjecture that they are elementarily equivalent. An analysis of the first-order … We show that Zilber's conjecture that complex exponentiation is isomorphic to his pseudo-exponentiation follows from the a priori simpler conjecture that they are elementarily equivalent. An analysis of the first-order types in pseudo-exponentiation leads to a description of the elementary embeddings, and the result that pseudo-exponential fields are precisely the models of their common first-order theory which are atomic over exponential transcendence bases. We also show that the class of all pseudo-exponential fields is an example of a nonfinitary abstract elementary class, answering a question of Kesälä and Baldwin.
A careful exposition of Zilber's quasiminimal excellent classes and their categoricity is given, leading to two new results: the L_w1,w(Q)-definability assumption may be dropped, and each class is determined by … A careful exposition of Zilber's quasiminimal excellent classes and their categoricity is given, leading to two new results: the L_w1,w(Q)-definability assumption may be dropped, and each class is determined by its model of dimension aleph_0.
In this paper, we briefly outline the definition of Zilber field, which is a structure analogue to the complex field with the exponential function. An open conjecture, including Schanuel’s Conjecture, … In this paper, we briefly outline the definition of Zilber field, which is a structure analogue to the complex field with the exponential function. An open conjecture, including Schanuel’s Conjecture, is whether the complex field is itself one of these structure. In view of this conjecture, a natural question raised by Zilber, Kirby, Macintyre and others is whether they have an automorphism of order two akin to complex conjugation. We announce, without proof, the positive answer: for cardinality up to the continuum there exists an involution of the field commuting with the exponential function. Moreover, in the case of cardinality of the continuum, the automorphism can be taken such that its fixed field is exactly ℝ , and the kernel of the exponential function is 2\pi i \mathbb Z .
The algebra of exponential fields and their extensions is developed. The focus is on ELA-fields, which are algebraically closed with a surjective exponential map. In this context, finitely presented extensions … The algebra of exponential fields and their extensions is developed. The focus is on ELA-fields, which are algebraically closed with a surjective exponential map. In this context, finitely presented extensions are defined, it is shown that finitely generated strong extensions are finitely presented, and these extensions are classified. An algebraic construction is given of Zilber's pseudo-exponential fields. As applications of the general results and methods of the paper, it is shown that Zilber's fields are not model-complete, answering a question of Macintyre, and a precise statement is given explaining how Schanuel's conjecture answers all transcendence questions about exponentials and logarithms. Connections with the Kontsevich-Zagier, Grothendieck, and Andr\'e transcendence conjectures on periods are discussed, and finally some open problems are suggested.