
toshikazu sunada

 ack japani ganitshastri aur ganit aur ganitiya vigyaan parr kaee pustakon aur nibandhon key lekhak hain. way meji vishvavidyalaya aur tohoku vishvavidyalaya donon key maanad professor hain. way ack shaikshanik jeevan key dauran upalabdhi kii maanyata mein meji mein emeritus key pratishthit professor bhee hain. 2003 mein meji vishvavidyalaya mein shamil honey seey pahale, way nagoya vishvavidyalaya (1988-1991), tokyo vishvavidyalaya (1991-1993) aur tohoku vishvavidyalaya (1993-2003) mein ganit key professor they. sunada meji vishvavidyalaya mein antahvishay ganitiya vigyaan key school key nirmaan mein shamil theen aur isake pahale deane (2013-2017) hain. 2019 seey, vaha japan kii ganit shiksha society key adhyaksh hain.
mukhya kaary.
sunada key kaam mein jatil vishleshanatmak jyaamiti, varnakramiya jyaamiti, gatishil pranaaliyan, sambhavana, graph siddhant, asatat jyaamitiya vishleshan aur ganitiya chrystallography shamil hain. unake kaee yogdaanon mein seey sabse prasiddh sambhaajak manifolds (1985) kaa ack samanya nirmaan haye, joe unake sankhya siddhant key jyaamitiya model parr adharit haye, aur ise maark kaak dwara prastaavit samasya mein ack safalata maanaa jaataa haye "kyaa koee drum key aakar koo suna sakata haye?"(drum key aakar koo sunana dekhein). sunada key vichaar koo carolin aiss ney apanaaya thaa. gorden, david web aur scott aeye. volpert jaba unhone kac kii samasya key liye ack prati-udaaharan kaa nirmaan kiya. iss kaam key liye, sunada koo 1987 mein ganitiya samaaj japan (msj) key ianaga puraskar seey sammaanit kiya gayaa thaa. unhein 2013 mein msj kaa prakaashan puraskar, 2017 mein ganitiya vigyaan key liye hiroshi fujiwara puraskar, 2018 mein vigyaan aur praudyogiki key liye puraskar (shiksha, sanskriti, khel, vigyaan aur praudyogiki mantri dwara vigyaan aur praudyogiki key liye prashansa) aur 2019 mein pahala kodaira kunihiko puraskar seey bhee sammaanit kiya gayaa thaa.
atsushi katsuda key saath ack sanyukt kaary mein, sunada ney gatishil pranaliyon (1988) key sandarbh mein ankganitiya pragati parr diriclet key pramey kaa ack jyaamitiya anuroop bhee sthaapit kiya. iss kaary key saath-saath uparokt kaary mein bhee dekhaa jaa sakata haye kii kaise samasyaon koo taiyar karane aur nae parinam dene key liye poori tarah seey alag-alag kshetron (jyaamiti, gatishil pranaaliyan aur sankhya siddhant) mein avadhaaranaon aur vichaaron koo ack saath rakhaa jaataa haye.
asatat jyaamitiya vishleshan key unake adhyayan mein ihara jeeta karyon kii ack graph-saiddhaantik vyakhya shamil haye, joe aavadhik chumbakiya schroedinger operators kaa ack asatat analogue haye aur saath hii chrystal jaali parr yaadrichhik chalane key badey samay key asymptotic vyavhaar bhee shamil hain. yaadrichhik chalane key adhyayan ney unhein kaalpanik chrystal (2005) key ack anant brahmand seey heere key chrystal key ack "ganitiya judvaan" kii khoj kii. unhone isaki ganitiya prasangikta key kaaran iska naam key4 chrystal rakhaa (link kiya gayaa lekh dekhein). unake dwara joe dekhaa gayaa vaha yeh haye kii key4 chrystal mein "majboot isotropy guna" haye, jiska arth haye kii chrystal nett key kissy bhee dou sheershon "aiks" aur "vaaee" key liye, aur "aiks" seey satey kinaaron key kissy bhee crum key liye aur "vaaee" seey satey kinaaron key kissy bhee crum key liye, ack shuddh-sanrakshan samroopata haye joe "aiks" koo "vaaee" taka leey jaati haye aur pratyek "aiks"-kinare koo samaan crum vaale "vaaee"-kinare taka leey jaati haye. yeh sampatti kewal heere key chrystal dwara saajha kii jaati haye 
(majboot samasthaanik koo kinare-sankramansheelta yaa samamit graph kii dhaarana key saath bhramit naheen kiya jaanaa chaahiye; udaaharan key liye, adim ghana jaali ack samamit graph haye, lekin dridhata seey samasthaanik naheen haye). antariksh mein network key roop mein key4 chrystal aur heere key chrystal "maanak praapti" key udaaharan hain, joe kalpana sunada aur motoko kotani dwara beejganitiya jyaamiti mein albeny maanchitron (ebel-jacoby maanchitra) key graph-saiddhaantik sanskaran key roop mein pesh kii gaee haye.
unake kaam key liye, isospectral, reinhart domen, ihara jeeta function, ramanujan graph, quantum ergodicity, quantum walk bhee dekhein.

