Abstract
A set of points in the plane is said to be in general position if no three of them are collinear and no four of them are cocircular. If a point set determines only distinct vectors, it is called parallelogram free. We show that there exist n-element point sets in the plane in general position, and parallelogram free, that determine only O(n 2/√log n) distinct distances. This answers a question of Erdős, Hickerson and Pach. We then revisit an old problem of Erdős: given any n points in the plane (or in d dimensions), how many of them can one select so that the distances which are determined are all distinct? — and provide (make explicit) some new bounds in one and two dimensions. Other related distance problems are also discussed.
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References
H. L. Abbott, Sidon sets, Canad. Math. Bull., 33 (1990), 335–341.
D. Avis, P. Erdős and J. Pach, Distinct distances determined by subsets of a point set in space, Comput. Geom., 1 (1991), 1–11.
N. Alon and J. Spencer, The Probabilistic Method, second edition, Wiley, New York, 2000.
J. Beck, On the lattice property of the plane and some problems of Dirac, Motzkin and Erdős in combinatorial geometry, Combinatorica, 3 (1983), 281–297.
F. Behrend, On sets of integers which contain no three in arithmetic progressions, Proc. Nat. Acad. Sci. U.S.A., 32 (1946), 331–332.
P. Braß, W. Moser and J. Pach, Research Problems in Discrete Geometry, Springer, New York, 2005.
F. Chung, The number of different distances determined by n points in the plane, J. Combin. Theory Ser. A, 36 (1984), 342–354.
F. Chung, E. Szemerédi and W. T. Trotter, The number of distinct distances determined by a set of points in the Euclidean plane, Discrete Comput. Geom., 7 (1992), 1–11.
K. L. Clarkson, H. Edelsbrunner, L. G. Guibas, M. Sharir and E. Welzl, Combinatorial complexity bounds for arrangements of curves and spheres, Discrete Comput. Geom., 5 (1990), 99–160.
A. Dumitrescu, On distinct distances and λ-free point sets, Discrete Math. (2007), doi:10.1016/j.disc.2007.11.046.
P. Erdős, On sets of distances of n points, Amer. Math. Monthly, 53 (1946), 248–250.
P. Erdős, Some remarks on set theory, Proc. Amer. Math. Soc., 1 (1950), 127–141.
P. Erdős, Néhány geometriai problémáról, Mat. Lapok, 8 (1957), 86–92 (in Hungarian); Mathematical Reviews, 20 (1959), pp. 6056.
P. Erdős, Some of my old and new problems in elementary number theory and geometry, Proceedings of the Sundance Conference on Combinatorics and Related Topics, Sundance, Utah, 1985; Congressus Numerantium, 50 (1985), 97–106.
P. Erdős, On some metric and combinatorial geometric problems, Discrete Math., 60 (1986), 147–153.
P. Erdős, Some old and new problems in combinatorial geometry, Applications of Discrete Mathematics (Clemson, SC, 1986), SIAM, Philadelphia, PA, 1988, 32–37.
P. Erdős, Some of my recent problems in combinatorial number theory, geometry and combinatorics, Graph Theory, Combinatorics, Algorithms and Applications, Vol. 1 (Y. Alavi et al, eds.), Wiley, 1995, 335–349.
P. Erdős, Z. Füredi, J. Pach and I. Z. Ruzsa, The grid revisited, Discrete Math., 111 (1993), 189–196.
P. Erdős and R. Guy, Distinct distances between lattice points, Elem. Math., 25 (1970), 121–123.
P. Erdős, D. Hickerson and J. Pach, A problem of Leo Moser about repeated distances on the sphere, Amer. Math. Monthly, 96 (1989), 569–575.
P. Erdős and G. Purdy, Extremal problems in combinatorial geometry, Handbook of Combinatorics, Vol. I (R. L. Graham, M. Grötschel, and L. Lovász, eds.), Elsevier, Amsterdam, 1995, 809–874.
P. Erdős and J. Surányi, Topics in the Theory of Numbers, second edition, Springer, New York, 2003.
P. Erdős and P. Turán, On a problem of Sidon in additive number theory, and on some related problems, J. London Math. Soc., 16 (1941), 212–215.
R. K. Guy, Unsolved Problems in Number Theory, third edition, Springer, New York, 2004.
G. H. Hardy and E. M. Wright, An Introduction to the Theory of Numbers, fifth edition, Oxford University Press, 1979.
N. Katz and G. Tardos, A new entropy inequality for the Erdős distance problem, Towards a Theory of Geometric Graphs (J. Pach, ed.), Contemporary Mathematics, AMS, 2004, 119–126.
J. Komlós, J. Pintz and E. Szemerédi, A lower bound for Heilbronn’s problem, J. London Math. Soc., 25 (1982), 13–24.
J. Komlós, M. Sulyok and E. Szemerédi, Linear problems in combinatorial number theory, Acta Math. Acad. Sci. Hungar., 26 (1975), 113–121.
H. Lefmann and T. Thiele, Point sets with distinct distances, Combinatorica, 15 (1995), 379–408.
B. Lindström, An inequality for B 2-sequences, J. Combin. Theory, 6 (1969), 211–212.
L. Moser, On different distances determined by n points, Amer. Math. Monthly, 59 (1952), 85–91.
J. Pach, Midpoints of segments induced by a point set, Geombinatorics, 13 (2003), 98–105.
J. Pach and P. K. Agarwal, Combinatorial Geometry, Wiley-Interscience, New York, 1995.
J. Pach and G. Tardos, Isosceles triangles determined by a planar point set, Graphs Combin., 18 (2002), 769–779.
C. Pomerance and A. Sárközy, Combinatorial Number Theory, Handbook of Combinatorics, Vol. I (R. L. Graham, M. Grötschel, and L. Lovász, eds.), Elsevier, Amsterdam, 1995, 967–1018.
S. Sidon, Ein Satz über trigonometrische Polynome und seine Anwendung in der Theorie der Fourier-Reihen, Math. Ann., 106 (1932), 536–539.
J. Singer, A theorem in finite projective geometry and some applications to number theory, Trans. Amer. Math. Soc., 43 (1938), 377–385.
J. Solymosi and Cs. D. Tóth, Distinct distances in the plane, Discrete Comput. Geom., 25 (2001), 629–634.
L. Székely, Crossing numbers and hard Erdős problems in discrete geometry, Combin. Probab. Comput., 6 (1997), 353–358.
G. Tardos, On distinct sums and distinct distances, Adv. Math., 180 (2003), 275–289.
T. Thiele, Geometric Selection Problems and Hypergraphs, Dissertation, Freie Universität Berlin, 1995.
T. Thiele, The no-four-on-circle problem, J. Combin. Theory Ser. A, 71 (1995), 332–334.
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Supported in part by NSF CAREER grant CCF-0444188.
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Dumitrescu, A. On distinct distances among points in general position and other related problems. Period Math Hung 57, 165–176 (2008). https://doi.org/10.1007/s10998-008-8165-4
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DOI: https://doi.org/10.1007/s10998-008-8165-4