Sergey Kislitsyn

{{short description|Russian mathematician}}

Sergey S. Kislitsyn, ({{langx|ru|Серге́й Серге́евич Кисли́цын}}) is a Russian mathematician, specializing in combinatorics and coding theory.

Kislitsyn was born January 5, 1935, in Ivanovo, Soviet Union. He received his M.S. in mathematics from Leningrad State University in 1957. From 1962 until 1970 he worked at Yekaterinburg branch of the Steklov Institute of Mathematics ({{ill|Krasovsky Institute of Mathematics and Mechanics|ru|Институт_математики_и_механики_имени_Н._Н._Красовского_УрО_РАН}}). He defended his Ph.D. thesis in 1964 and continued working as a lecturer at Krasnoyarsk State University.{{cite book |url=https://umj.uran.ru/list_1975/List.pdf |pages=87–89 |language=ru |chapter=Кислицын Сергей Сергеевич |title=Биобиблиографический Указатель Научных Трудов Сотрудников Института Математики и Механики УрО РАН до 1975 г |trans-title=Bio-Bibliographic Index of Scientific Works of Employees of the Institute of Mathematics and Mechanics UB RAS before 1975 |volume=1 |publisher=Ural Branch of the Russian Academy of Sciences |location=Yekaterinburg, Russia |year=2010}}

Kislitsyn is known for posing the 1/3–2/3 conjecture for linear extensions of finite posets, which he published in 1968.{{cite journal

| last = Kislitsyn | first = S. S.

| doi = 10.1007/BF01111312

| issue = 5

| journal = Mathematical Notes

| pages = 798–801

| title = A finite partially ordered set and its corresponding set of permutations

| volume = 4

| year = 1968| s2cid = 120228193

}} The conjecture is established in several special cases but open in full generality.{{cite journal

| last1 = Olson | first1 = Emily J.

| last2 = Sagan | first2 = Bruce E.

| doi = 10.1007/s11083-017-9450-3

| issue = 3

| journal = Order

| mr = 3861401

| pages = 581–596

| title = On the 1/3–2/3 conjecture

| volume = 35

| year = 2018| s2cid = 52965439

}}{{cite journal |last=Brightwell |first=Graham |date=1999-04-28 |title=Balanced pairs in partial orders |journal=Discrete Mathematics |language=en |volume=201 |issue=1 |pages=25–52 |doi=10.1016/S0012-365X(98)00311-2 |issn=0012-365X|doi-access= }}