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Xavier Buff 
            
On postcritically finite unicritical polynomials 
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                | Published: | 
                December 11, 2018. | 
               
              
                | Keywords: | 
                Preperiodic points, unicritical polynomial, post-critically finite, arithmetic dynamics, complex dynamics. | 
               
              
                | Subject: | 
                37P05, 37P35, 37F45. | 
               
              
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			  Abstract
			  
In this article, we first study arithmetical properties of postcritically finite unicritical polynomials fa:z → azD+1 with D
≥ 2. In particular, we answer a question of Milnor, showing that there exist non-Galois conjugate parameters a1 ∈ C and a2
∈ C such that fa1 and fa2 have critical orbits periodic with the same period. We also answer a question of Baker and DeMarco, proving that the set of parameters a ∈ C such that 0 and 1 are simultaneously (pre)periodic for qa:w → w2+a is equal to {0,-1,-2}.  | 
           
			
			  
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			  | Acknowledgements
		       This research was supported in part by the ANR grant Lambda ANR-13-BS01-0002.
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			  | Author information
 Xavier Buff: 
Institut de Mathématiques de Toulouse 
UMR5219, Université de Toulouse  
CNRS, UPS, F-31062 Toulouse Cedex 9, France 
xavier.buff@math.univ-toulouse.fr 
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