Nous démontrons un théorème , dans sa version la plus complète, pour les ensembles de réels en utilisant des idées issues du travail de Ruzsa sur les mesures des sommes d’ensembles de réels et une représentation graphique liée à la densité des ensembles. Nous obtenons ainsi des informations sur les structures des ensembles , et lorsque et soit la mesure de est supérieure à celle de , soit le diamètre de est supérieur à celui de . Nous obtenons aussi des informations sur la structure des ensembles de grande densité en fonction de la taille de leur somme, ce qui représente un résultat n’ayant pas d’analogue discret. Nous caractérisons enfin les ensembles de réels critiques pour lesquels la mesure de l’ensemble somme atteint le minorant que nous avons obtenu.
We prove a full continuous Freiman’s theorem for small sumsets in by using some ideas from Ruzsa’s work on measure of sumsets in as well as some graphic representation of density functions of sets. We thereby get some structural properties of , and when and either or has larger diameter than . We also give some structural information for sets of large density according to the size of their sumset, a result so far unknown in the discrete and the continuous setting. Finally, we characterise the critical sets for which equality holds in the lower bounds for .
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DOI : 10.5802/jep.67
Keywords: Sumsets, critical sets, Lebesgue measure, inverse theorems in additive combinatorics
Mot clés : Ensembles sommes, ensembles critiques, mesure de Lebesgue, théorèmes inverses en combinatoire additive
Anne de Roton 1
@article{JEP_2018__5__177_0, author = {Anne de Roton}, title = {Small sumsets in $\protect \mathbb{R}$: full continuous $3k-4$ theorem, critical sets}, journal = {Journal de l{\textquoteright}\'Ecole polytechnique {\textemdash} Math\'ematiques}, pages = {177--196}, publisher = {\'Ecole polytechnique}, volume = {5}, year = {2018}, doi = {10.5802/jep.67}, zbl = {06988577}, mrnumber = {3738512}, language = {en}, url = {https://jep.centre-mersenne.org/articles/10.5802/jep.67/} }
TY - JOUR AU - Anne de Roton TI - Small sumsets in $\protect \mathbb{R}$: full continuous $3k-4$ theorem, critical sets JO - Journal de l’École polytechnique — Mathématiques PY - 2018 SP - 177 EP - 196 VL - 5 PB - École polytechnique UR - https://jep.centre-mersenne.org/articles/10.5802/jep.67/ DO - 10.5802/jep.67 LA - en ID - JEP_2018__5__177_0 ER -
%0 Journal Article %A Anne de Roton %T Small sumsets in $\protect \mathbb{R}$: full continuous $3k-4$ theorem, critical sets %J Journal de l’École polytechnique — Mathématiques %D 2018 %P 177-196 %V 5 %I École polytechnique %U https://jep.centre-mersenne.org/articles/10.5802/jep.67/ %R 10.5802/jep.67 %G en %F JEP_2018__5__177_0
Anne de Roton. Small sumsets in $\protect \mathbb{R}$: full continuous $3k-4$ theorem, critical sets. Journal de l’École polytechnique — Mathématiques, Tome 5 (2018), pp. 177-196. doi : 10.5802/jep.67. https://jep.centre-mersenne.org/articles/10.5802/jep.67/
[BG10] - “Long arithmetic progressions in small sumsets”, Integers 10 (2010), p. 335-350 | DOI | MR | Zbl
[Bil98] - “The -inequality on a torus”, J. London Math. Soc. (2) 57 (1998) no. 3, p. 513-528 | DOI | MR | Zbl
[Chr11] - “An approximate inverse Riesz-Sobolev inequality” (2011), arXiv:1112.3715
[EGM14] - “Sets of integers with no large sum-free subset”, Ann. of Math. (2) 180 (2014) no. 2, p. 621-652 | DOI | MR | Zbl
[Fre59] - “The addition of finite sets. I”, Izv. Vysš. Učebn. Zaved. Matematika 1959 (1959) no. 6 (13), p. 202-213 | DOI | MR | Zbl
[Fre62] - “Inverse problems of additive number theory. VI. On the addition of finite sets. III”, Izv. Vysš. Učebn. Zaved. Matematika 1962 (1962) no. 3 (28), p. 151-157 | MR | Zbl
[Fre09] - “Inverse additive number theory. XI. Long arithmetic progressions in sets with small sumsets”, Acta Arith. 137 (2009) no. 4, p. 325-331 | MR | Zbl
[Gry13] - Structural additive theory, Developments in Mathematics, vol. 30, Springer, Cham, 2013 | MR
[Kne56] - “Summenmengen in lokalkompakten abelschen Gruppen”, Math. Z. 66 (1956), p. 88-110 | DOI | MR | Zbl
[LS95] - “On addition of two distinct sets of integers”, Acta Arith. 70 (1995) no. 1, p. 85-91 | DOI | MR | Zbl
[Nat96] - Additive number theory, Graduate Texts in Math., vol. 165, Springer-Verlag, New York, 1996 | MR | Zbl
[Rai39] - “On the addition of point-sets in the sense of Schnirelmann”, Mat. Sb. (N.S.) 5(47) (1939), p. 425-440 | MR | Zbl
[Ruz91] - “Diameter of sets and measure of sumsets”, Monatsh. Math. 112 (1991) no. 4, p. 323-328 | DOI | MR | Zbl
[Sta96] - “On addition of two distinct sets of integers”, Acta Arith. 75 (1996) no. 2, p. 191-194 | DOI | MR | Zbl
[TV06] - Additive combinatorics, Cambridge Studies in Advanced Mathematics, vol. 105, Cambridge University Press, Cambridge, 2006 | MR | Zbl
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