Е. Деза_ М.М. Деза. Энциклопедический словарь расстояний (2008) (1185330), страница 44
Текст из файла (страница 44)
(p, q)ÓÚÌÓÒËÚÂθ̇fl ÏÂÚË͇, „Î. 19), ÓÔ‰ÂÎflÂÏÛ˛ ͇Í|z−u|(| z | + | u | p )1 / pp‰Îfl | z | + | u | ≠ 0 (Ë ‡‚ÌÛ˛ 0, Ë̇˜Â); ‰Îfl p = 0 ÔÓÎÛ˜‡ÂÏ ÓÚÌÓÒËÚÂθÌÛ˛ ÏÂÚËÍÛ,Á‡‰‡‚‡ÂÏÛ˛ ‰Îfl | z | + | u | ≠ 0 ͇Í|z−u|.max{| z |, | u |}ïÓ‰‡Î¸Ì‡fl ÏÂÚË͇ïÓ‰‡Î¸Ì‡fl ÏÂÚË͇ d χ ÂÒÚ¸ ÏÂÚË͇ ̇ ÏÌÓÊÂÒÚ‚Â = ∪ {∞}, ÓÔ‰ÂÎÂÌ̇fl ͇Ídχ ( z, u) =2|z−u|1+ | z |2 1+ | u |2‰Îfl ‚ÒÂı z, u ∈ Ë Í‡Ídχ ( z, ∞) =21+ | z |2‰Îfl ‚ÒÂı z ∈ (ÒÏ. å-ÓÚÌÓÒËÚÂθ̇fl ÏÂÚË͇, „Î. 19). åÂÚ˘ÂÒÍÓ ÔÓÒÚ‡ÌÒÚ‚Ó192ó‡ÒÚ¸ III. ê‡ÒÒÚÓflÌËfl ‚ Í·ÒÒ˘ÂÒÍÓÈ Ï‡ÚÂχÚËÍÂ( , dχ ) ̇Á˚‚‡ÂÚÒfl ‡Ò¯ËÂÌÌÓÈ ÍÓÏÔÎÂÍÒÌÓÈ ÔÎÓÒÍÓÒÚ¸˛.
é̇ „ÓÏÂÓÏÓÙ̇ ËÍÓÌÙÓÏÌÓ ˝Í‚Ë‚‡ÎÂÌÚ̇ ËχÌÓ‚ÓÈ ÒÙÂÂ.àÏÂÌÌÓ, ËχÌÓ‚‡ ÒÙ‡ – ˝ÚÓ ÒÙ‡ ‚ ‚ÍÎˉӂÓÏ ÔÓÒÚ‡ÌÒÚ‚Â 3 , ‡ÒÒχÚË‚‡Âχfl Í‡Í ÏÂÚ˘ÂÒÍÓ ÔÓ‰ÔÓÒÚ‡ÌÒÚ‚Ó 3 , ̇ ÍÓÚÓÛ˛ ‚ ÒÚÂÂÓ„‡Ù˘ÂÒÍÓÈ ÔÓÂ͈ËË ‚Á‡ËÏÌÓ-Ó‰ÌÓÁ̇˜ÌÓ ÓÚÓ·‡Ê‡ÂÚÒfl ‡Ò¯ËÂÌ̇fl ÍÓÏÔÎÂÍÒ̇flÔÎÓÒÍÓÒÚ¸. Ö‰ËÌ˘ÌÛ˛ ÒÙÂÛ S 2 = {( x1 , x 2 , x3 ) ∈ 3 : x12 + x 22 + x32 = 1} ÏÓÊÌÓ ‡ÒÒχÚË‚‡Ú¸ Í‡Í ËχÌÓ‚Û ÒÙÂÛ, ‡ ÔÎÓÒÍÓÒÚ¸ ÏÓÊÌÓ ÓÚÓʉÂÒÚ‚ËÚ¸ Ò ÔÎÓÒÍÓÒÚ¸˛x3 = 0 Ú‡Í, ˜ÚÓ Â ‰ÂÈÒÚ‚ËÚÂθ̇fl ÓÒ¸ ÒÓ‚Ô‡‰‡ÂÚ Ò x1-ÓÒ¸˛, ‡ ÏÌËχfl ÓÒ¸ – Ò x2-ÓÒ¸˛.èË ÒÚÂÂÓ„‡Ù˘ÂÒÍÓÈ ÔÓÂ͈ËË Í‡Ê‰‡fl ÚӘ͇ z ∈ ÒÓÓÚ‚ÂÚÒÚ‚ÛÂÚ ÚÓ˜ÍÂ(x 1 , x2, x3) ∈ S 2 , ÍÓÚÓ‡fl ÔÓÎÛ˜Â̇ Í‡Í ÚӘ͇ ÔÂÂÒ˜ÂÌËfl ÎÛ˜‡, Ôӂ‰ÂÌÌÓ„Ó ËÁ"Ò‚ÂÌÓ„Ó ÔÓÎ˛Ò‡" (0, 0, 1) ÒÙÂ˚ ‚ ÚÓ˜ÍÛ z ÒÙÂ˚ S2 ; "Ò‚ÂÌ˚È ÔÓβÒ"ÒÓÓÚ‚ÂÚÒÚ‚ÛÂÚ ·ÂÒÍÓ̘ÌÓ Û‰‡ÎÂÌÌÓÈ ÚÓ˜ÍÂ.
ïÓ‰‡Î¸ÌÓ ‡ÒÒÚÓflÌË ÏÂÊ‰Û ‰‚ÛÏflÚӘ͇ÏË p, q ∈ S2 ÓÔ‰ÂÎflÂÚÒfl Í‡Í ‡ÒÒÚÓflÌË ÏÂÊ‰Û Ëı ÔÓÓ·‡Á‡ÏË z, u ∈.ïÓ‰‡Î¸Ì‡fl ÏÂÚË͇ ÏÓÊÂÚ ·˚Ú¸ ‡Ì‡Îӄ˘Ì˚Ï Ó·‡ÁÓÏ ÓÔ‰ÂÎÂ̇ ̇n = n ∪ {∞}. àÏÂÌÌÓ ‰Îfl β·˚ıdχ ( x, y) =2 || x − y ||21 + || x ||22 1 + || y ||22Ë ‰Îfl β·Ó„Ó x ∈ ndχ ( x, ∞) =21 + || x ||22,„‰Â || ⋅ ||2 – Ó·˚˜Ì‡fl ‚ÍÎˉӂ‡ ÌÓχ ̇ n. åÂÚ˘ÂÒÍÓ ÔÓÒÚ‡ÌÒÚ‚Ó (n, dχ) ̇Á˚‚‡ÂÚÒfl ÔÓÒÚ‡ÌÒÚ‚ÓÏ åfi·ËÛÒ‡. ùÚÓ ÔÚÓÎÂÏÂÂ‚Ó ÏÂÚ˘ÂÒÍÓ ÔÓÒÚ‡ÌÒÚ‚Ó(ÒÏ. èÚÓÎÂÏ‚‡ ÏÂÚË͇, „Î.1).ÖÒÎË Á‡‰‡Ì˚ α > 0, β ≥ 0, p ≥ 1, ÚÓ Ó·Ó·˘ÂÌÌÓÈ ıÓ‰‡Î¸ÌÓÈ ÏÂÚËÍÓÈ Ì‡Á˚‚‡ÂÚÒflÏÂÚË͇ ̇ (‚ Ó·˘ÂÏ ÒÎÛ˜‡Â ̇ ( n , || ⋅ ||2 ) Ë ‰‡Ê ̇ β·ÓÏ ÔÚÓÎÂÏ‚ÓÏÔÓÒÚ‡ÌÒÚ‚Â (V , || ⋅ ||)), ÓÔ‰ÂÎÂÌ̇fl ͇Í|z−u|.(α + β | z | ) ⋅ (α + β | u | p )1 / pp 1/ pé̇ ΄ÍÓ Ó·Ó·˘‡ÂÚÒfl Ë Ì‡ ÒÎÛ˜‡È ( n ).䂇ÚÂÌËÓÌ̇fl ÏÂÚË͇䂇ÚÂÌËÓÌ˚ – ˝ÎÂÏÂÌÚ˚ ÌÂÍÓÏÏÛÚ‡ÚË‚ÌÓÈ ‡Î„·˚ Ò ‰ÂÎÂÌËÂÏ Ì‡‰ ÔÓÎÂÏ ,„ÂÓÏÂÚ˘ÂÒÍË Â‡ÎËÁÛÂÏ˚ ‚ ˜ÂÚ˚ÂıÏÂÌÓÏ ÔÓÒÚ‡ÌÒÚ‚Â ([Hami66]).
䂇ÚÂÌËÓÌ ÏÓÊÌÓ Á‡ÔËÒ‡Ú¸ ‚ ÙÓÏ q = q1 + q2 i + q3 j + q4 k , qi ∈ , „‰Â Í‚‡ÚÂÌËÓÌ˚ i, j Ëk ̇Á˚‚‡˛ÚÒfl ÓÒÌÓ‚Ì˚ÏË Â‰ËÌˈ‡ÏË Ë Û‰Ó‚ÎÂÚ‚Ófl˛Ú ÒÎÂ‰Û˛˘ËÏ ÒÓÓÚÌÓ¯ÂÌËflÏ,ËÁ‚ÂÒÚÌ˚Ï Í‡Í Ô‡‚Ë· ɇÏËθÚÓ̇: i2 = j2 = k2 = –1 Ë ij = –ji = k.çÓχ || q || Í‚‡ÚÂÌËÓ̇ q = q1 + q2 i + q3j + q3k ∈ ÓÔ‰ÂÎflÂÚÒfl ͇Í|| q ||= qq = q12 + q22 + q32 + q42 ,q = q1 − q2 i − q3 j − q4 k.䂇ÚÂÌËÓÌ̇fl ÏÂÚË͇ ÂÒÚ¸ ÏÂÚË͇ ÌÓÏ˚ ̇ ÏÌÓÊÂÒÚ‚Â ‚ÒÂı Í‚‡ÚÂÌËÓÌÓ‚, ÓÔ‰ÂÎflÂÏÓÈ Í‡Í || x − y || .193É·‚‡ 12. ê‡ÒÒÚÓflÌËfl ̇ ˜ËÒ·ı, ÏÌÓ„Ó˜ÎÂ̇ı Ë Ï‡Úˈ‡ı12.2.
êÄëëíéüçàü çÄ åçéÉéóãÖçÄïåÌÓ„Ó˜ÎÂÌ – ‚˚‡ÊÂÌËÂ, fl‚Îfl˛˘ÂÂÒfl ÒÛÏÏÓÈ ÒÚÂÔÂÌÂÈ Ó‰ÌÓÈ ËÎË ÌÂÒÍÓθÍËıÔÂÂÏÂÌÌ˚ı, ÛÏÌÓÊÂÌÌ˚ı ̇ ÍÓ˝ÙÙˈËÂÌÚ˚. åÌÓ„Ó˜ÎÂÌ ÓÚ Ó‰ÌÓÈ ÔÂÂÏÂÌÌÓÈ Ò‰ÂÈÒÚ‚ËÚÂθÌ˚ÏË (ÍÓÏÔÎÂÍÒÌ˚ÏË) ÍÓ˝ÙÙˈËÂÌÚ‡ÏË Á‡‰‡ÂÚÒfl Í‡Í P = P( z ) =n=∑ ak z k ,ak ∈ ( ak ∈ ). åÌÓÊÂÒÚ‚Ó ‚ÒÂı ‰ÂÈÒÚ‚ËÚÂθÌ˚ı (ÍÓÏÔÎÂÍÒÌ˚ı)k =0ÏÌÓ„Ó˜ÎÂÌÓ‚ Ó·‡ÁÛ˛Ú ÍÓθˆÓ (, +, ⋅, 0). éÌÓ fl‚ÎflÂÚÒfl Ú‡ÍÊ ‚ÂÍÚÓÌ˚Ï ÔÓÒÚ‡ÌÒÚ‚ÓÏ Ì‡‰ (̇‰ ).åÂÚË͇ ÌÓÏ˚ ÏÌÓ„Ó˜ÎÂ̇åÂÚË͇ ÌÓÏ˚ ÏÌÓ„Ó˜ÎÂ̇ ÂÒÚ¸ ÏÂÚË͇ ÌÓÏ˚ ̇ ÏÌÓÊÂÒÚ‚Â ‚ÒÂı ‰ÂÈÒÚ‚ËÚÂθÌ˚ı (ÍÓÏÔÎÂÍÒÌ˚ı) ÏÌÓ„Ó˜ÎÂÌÓ‚, ÓÔ‰ÂÎÂÌ̇fl ͇Í|| P – Q ||,„‰Â || ⋅ || – ÌÓχ ÏÌÓ„Ó˜ÎÂ̇, Ú.Â.
ڇ͇fl ÙÛÌ͈Ëfl || ⋅ ||: → , ˜ÚÓ ‰Îfl ‚ÒÂı P, Q ∈ Ëβ·Ó„Ó Ò͇Îfl‡ k ËÏÂÂÏ ÒÎÂ‰Û˛˘Ë ҂ÓÈÒÚ‚‡:1) || P || ≥ 0 Ò || P || = 0 ÚÓ„‰‡ Ë ÚÓθÍÓ ÚÓ„‰‡, ÍÓ„‰‡ P = 0;2) || kP || = | k | || P ||;3) || P + Q || ≤ || P || + || Q || (̇‚ÂÌÒÚ‚Ó ÚÂÛ„ÓθÌË͇).ÑÎfl ÏÌÓÊÂÒÚ‚‡ Ó·˚˜ÌÓ ËÒÔÓθÁÛ˛ÚÒfl ÌÂÒÍÓθÍÓ Í·ÒÒÓ‚ ÌÓÏ. lp -ÌÓχn∑ ak z k ÓÔ‰ÂÎflÂÚÒfl ͇Í(1 ≤ p ≤ ∞) ÏÌÓ„Ó˜ÎÂ̇ P( z ) =k =0 n|| P || p = | ak | p k =0∑n‰‡‚‡fl ÓÒÓ·˚ ÒÎÛ˜‡Ë || P ||1 =∑1/ p,n| ak |, || P ||2 =k =0∑| ak | 2Ë || P ||∞ = max | ak | .k =00≤k ≤ná̇˜ÂÌË || P ||∞ ̇Á˚‚‡ÂÚÒfl ‚˚ÒÓÚÓÈ ÏÌÓ„Ó˜ÎÂ̇.
Lp -ÌÓχ (1 ≤ p ≤ ∞) ÏÌÓ„Ó˜ÎÂ̇nP( z ) =∑ ak z k ÓÔ‰ÂÎflÂÚÒfl ͇Ík =0PLp2π‰‡‚‡fl ÓÒÓ·˚ ÒÎÛ˜‡ËLL1=∫0 2πdθ | P(e iθ ) | p=2 π 01/ p∫dθ| P(e ) |, P2π,2πiθL2=∫0| P(e iθ ) |dθË2πPL∞== sup | P( z ) | .|z | = 1åÂÚË͇ ÅÓÏ·¸ÂËåÂÚË͇ ÅÓÏ·¸ÂË (ËÎË ÒÍӷӘ̇fl ÏÂÚË͇ ÏÌÓ„Ó˜ÎÂ̇) ÂÒÚ¸ ÏÂÚË͇ ÌÓÏ˚ÏÌÓ„Ó˜ÎÂ̇ ̇ ÏÌÓÊÂÒÚ‚Â ‚ÒÂı ‰ÂÈÒÚ‚ËÚÂθÌ˚ı (ÍÓÏÔÎÂÍÒÌ˚ı) ÏÌÓ„Ó˜ÎÂÌÓ‚,194ó‡ÒÚ¸ III. ê‡ÒÒÚÓflÌËfl ‚ Í·ÒÒ˘ÂÒÍÓÈ Ï‡ÚÂχÚËÍÂÓÔ‰ÂÎÂÌ̇fl ͇Í[P – Q]p ,n„‰Â [⋅]p , 0 ≤ p ≤ ∞, ÂÒÚ¸ -ÌÓχ ÅÓÏ·¸ÂË. ÑÎfl ÏÌÓ„Ó˜ÎÂ̇ P( z ) =∑ ak z k Ó̇ Á‡‰‡-k =0ÂÚÒfl Í‡Í n n 1− p[ P] p = | ak | p k = 0 k∑1/ p, n„‰Â – ·ËÌÓÏˇθÌ˚È ÍÓ˝ÙÙˈËÂÌÚ. k12.3. êÄëëíéüçàü çÄ åÄíêàñÄïm × n χÚˈ‡ A = ((aij)) ̇‰ ÔÓÎÂÏ Ô‰ÒÚ‡‚ÎflÂÚ ÒÓ·ÓÈ Ú‡·ÎˈÛ, ÒÓÒÚÓfl˘Û˛ ËÁ mÒÚÓÍ Ë n ÒÚÓηˆÓ‚ Ò ˝ÎÂÏÂÌÚ‡ÏË aij ËÁ ÔÓÎfl .
åÌÓÊÂÒÚ‚Ó ‚ÒÂı m × n χÚˈ Ò‰ÂÈÒÚ‚ËÚÂθÌ˚ÏË (ÍÓÏÔÎÂÍÒÌ˚ÏË) ˝ÎÂÏÂÌÚ‡ÏË Ó·ÓÁ̇˜‡ÂÚÒfl Í‡Í Mm,n. éÌÓ Ó·‡ÁÛÂÚ „ÛÔÔÛ (M m,n, +, 0m,n), „‰Â ((aij)) + ((bij)) = ((aij + bij)), ‡ χÚˈ‡ 0m,n ≡ 0, Ú.Â. ‚Ҡ½ÎÂÏÂÌÚ˚ ‡‚Ì˚ 0. éÌÓ fl‚ÎflÂÚÒfl Ú‡ÍÊ mn-ÏÂÌ˚Ï ‚ÂÍÚÓÌ˚Ï ÔÓÒÚ‡ÌÒÚ‚ÓÏ Ì‡‰ (̇‰ ).
í‡ÌÒÔÓÌËÓ‚‡ÌÌÓÈ Ï‡ÚˈÂÈ ‰Îfl χÚˈ˚ A = ((aij)) ∈ Mm,n ̇Á˚‚‡ÂÚÒflχÚˈ‡ AT = ((aij)) ∈ M n , m . ëÓÔflÊÂÌÌÓÈ Ú‡ÌÒÔÓÌËÓ‚‡ÌÌÓÈ Ï‡ÚˈÂÈ (ËÎËÔËÒÓ‰ËÌÂÌÌÓÈ Ï‡ÚˈÂÈ) ‰Îfl χÚˈ˚ A = ((a i j)) ∈ M m,n ̇Á˚‚‡ÂÚÒfl χÚˈ‡A∗ = (( aij )) ∈ Mn, m .å‡Úˈ‡ ̇Á˚‚‡ÂÚÒfl Í‚‡‰‡ÚÌÓÈ Ï‡ÚˈÂÈ, ÂÒÎË m = n.
åÌÓÊÂÒÚ‚Ó ‚ÒÂı Í‚‡‰‡ÚÌ˚ı n × n χÚˈ Ò ‰ÂÈÒÚ‚ËÚÂθÌ˚ÏË (ÍÓÏÔÎÂÍÒÌ˚ÏË) ˝ÎÂÏÂÌÚ‡ÏË Ó·ÓÁ̇˜‡ÂÚÒflÍ‡Í M n . éÌÓ Ó·‡ÁÛÂÚ ÍÓθˆÓ (Mn , +, 0), „‰Â + Ë 0n ÓÔ‰ÂÎfl˛ÚÒfl Í‡Í Û͇Á‡ÌÓ ‚˚¯Â, n‡ (( aij )) ⋅ ((bij )) = aik bkj . éÌÓ fl‚ÎflÂÚÒfl Ú‡ÍÊ n2 -ÏÂÌ˚Ï ‚ÂÍÚÓÌ˚Ï ÔÓ k =1ÒÚ‡ÌÒÚ‚ÓÏ Ì‡‰ (̇‰ ). å‡Úˈ‡ A = ((aij)) ∈ M n ̇Á˚‚‡ÂÚÒfl ÒËÏÏÂÚ˘ÌÓÈ, ÂÒÎËaij = a j i ‰Îfl ‚ÒÂı i, j ∈ {1,…, n}, Ú.Â., ÂÒÎË A = A T.
ëÔˆˇθÌ˚Ï ÒÎÛ˜‡ÂÏ ÚËÔ˚Í‚‡‰‡ÚÌ˚ı n × n χÚˈ fl‚ÎflÂÚÒfl ‰ËÌ˘̇fl χÚˈ‡ 1n = ((c ij)) Ò cii = 1 Ë cij = 0,i ≠ j. ìÌËڇ̇fl χÚˈ‡ U = ((u ij)) ÂÒÚ¸ Í‚‡‰‡Ú̇fl χÚˈ‡, ÓÔ‰ÂÎÂÌ̇fl ͇ÍU –1 = U*, „‰Â U –1 – Ó·‡Ú̇fl χÚˈ‡ ‰Îfl U, Ú.Â. U ⋅ U –1 = 1n . éÚÓ„Ó̇θÌÓÈχÚˈÂÈ Ì‡Á˚‚‡ÂÚÒfl χÚˈ‡ A ∈ Mm,n, ڇ͇fl ˜ÚÓ A* A = 1 n .ÖÒÎË ‰Îfl χÚˈ˚ A ∈ Mn ÒÛ˘ÂÒÚ‚ÛÂÚ ‚ÂÍÚÓ ı, Ú‡ÍÓÈ ˜ÚÓ Ax = λx ‰Îfl ÌÂÍÓÚÓÓ„ÓÒ͇Îfl‡ λ, ÚÓ λ ̇Á˚‚‡ÂÚÒfl ÒÓ·ÒÚ‚ÂÌÌ˚Ï Á̇˜ÂÌËÂÏ Ï‡Úˈ˚ Ä, ÒÓÓÚ‚ÂÚÒÚ‚Û˛˘ËÏ ÒÓ·ÒÚ‚ÂÌÌÓÏÛ ‚ÂÍÚÓÛ ı. ÑÎfl ÍÓÏÔÎÂÍÒÌÓÈ Ï‡Úˈ˚ A ∈ Mm,n,  ÒËÌ„ÛÎflÌ˚ÂÁ̇˜ÂÌËfl s i(A) ÓÔ‰ÂÎfl˛ÚÒfl Í‡Í Í‚‡‰‡ÚÌ˚ ÍÓÌË ÒÓ·ÒÚ‚ÂÌÌ˚ı Á̇˜ÂÌËÈ Ï‡Úˈ˚A* A, „‰Â A* – ÒÓÔflÊÂÌ̇fl Ú‡ÌÒÔÓÌËÓ‚‡Ì̇fl χÚˈ‡ ‰Îfl Ä. éÌË fl‚Îfl˛ÚÒflÌÂÓÚˈ‡ÚÂθÌ˚ÏË ‰ÂÈÒÚ‚ËÚÂθÌ˚ÏË ˜ËÒ·ÏË, Ô˘ÂÏ s 1 (A) ≥ s2 (A) ≥ … .∑åÂÚË͇ ÌÓÏ˚ χÚˈ˚åÂÚËÍÓÈ ÌÓÏ˚ χÚˈ˚ ̇Á˚‚‡ÂÚÒfl ÏÂÚË͇ ÌÓÏ˚ ̇ ÏÌÓÊÂÒÚ‚Â Mm,n ‚ÒÂı‰ÂÈÒÚ‚ËÚÂθÌ˚ı (ÍÓÏÔÎÂÍÒÌ˚ı) m × n χÚˈ, ÓÔ‰ÂÎÂÌ̇fl ͇Í|| A – B ||,É·‚‡ 12.
ê‡ÒÒÚÓflÌËfl ̇ ˜ËÒ·ı, ÏÌÓ„Ó˜ÎÂ̇ı Ë Ï‡Úˈ‡ı195„‰Â || ⋅ || – ÌÓχ χÚˈ˚, Ú.Â. ڇ͇fl ÙÛÌ͈Ëfl || ⋅ ||: M m , n → , ˜ÚÓ ‰Îfl ‚ÒÂıA, B ∈ Mm,n Ë ‰Îfl β·Ó„Ó Ò͇Îfl‡ k ËÏÂ˛Ú ÏÂÒÚÓ ÒÎÂ‰Û˛˘Ë ҂ÓÈÒÚ‚‡:1) || A || ≥ 0 Ò || A || = 0 ÚÓ„‰‡ Ë ÚÓθÍÓ ÚÓ„‰‡, ÍÓ„‰‡ A = 0m,n;2) || kA || k | || A ||;3) || A + B || ≤ || A || + || B || (̇‚ÂÌÒÚ‚Ó ÚÂÛ„ÓθÌË͇).ÇÒ ÏÂÚËÍË ÌÓÏ˚ χÚˈ˚ ̇ M m,n ˝Í‚Ë‚‡ÎÂÌÚÌ˚. çÓχ χÚˈ˚ || ⋅ || ̇ÏÌÓÊÂÒÚ‚Â M n ‚ÒÂı ‰ÂÈÒÚ‚ËÚÂθÌ˚ı (ÍÓÏÔÎÂÍÒÌ˚ı) Í‚‡‰‡ÚÌ˚ı n × n χÚˈ̇Á˚‚‡ÂÚÒfl ÒÛ·ÏÛθÚËÔÎË͇ÚË‚ÌÓÈ, ÂÒÎË Ó̇ ÒÓ‚ÏÂÒÚËχ Ò ÛÏÌÓÊÂÌËÂÏ Ï‡Úˈ,Ú.Â.
|| AB || ≤ || A || ⋅ || B || ‰Îfl ‚ÒÂı A, B ∈ Mn . åÌÓÊÂÒÚ‚Ó Mn Ò ÒÛ·ÏÛθÚËÔÎË͇ÚË‚ÌÓÈÌÓÏÓÈ fl‚ÎflÂÚÒfl ·‡Ì‡ıÓ‚ÓÈ ‡Î„·ÓÈ.èÓÒÚÂȯËÏ ÔËÏÂÓÏ ÏÂÚËÍË ÌÓÏ˚ χÚˈ˚ fl‚ÎflÂÚÒfl ı˝ÏÏË̄ӂ‡ ÏÂÚË͇̇ Mm,n (‚ Ó·˘ÂÏ ÒÎÛ˜‡Â ̇ ÏÌÓÊÂÒÚ‚Â Mm,n() ‚ÒÂı χÚˈ m × n Ò ˝ÎÂÏÂÌÚ‡ÏË ËÁÔÓÎfl ), ÓÔ‰ÂÎÂÌ̇fl Í‡Í || A – B ||H, „‰Â || A || H – ÌÓχ ï˝ÏÏËÌ„‡ χÚˈ˚A ∈ Mm,n, Ú.Â.
˜ËÒÎÓ ÌÂÌÛ΂˚ı ˝ÎÂÏÂÌÚÓ‚ χÚˈ˚ Ä.åÂÚË͇ ÂÒÚÂÒÚ‚ÂÌÌÓÈ ÌÓÏ˚åÂÚË͇ ÂÒÚÂÒÚ‚ÂÌÌÓÈ ÌÓÏ˚ (ËÎË Ë̉ۈËÓ‚‡Ì̇fl ÏÂÚË͇ ÌÓÏ˚, ÔÓ‰˜ËÌÂÌ̇fl ÏÂÚË͇ ÌÓÏ˚) ÂÒÚ¸ ÏÂÚË͇ ÌÓÏ˚ ̇ ÏÌÓÊÂÒÚ‚Â Mn ‚ÒÂı ‰ÂÈÒÚ‚ËÚÂθÌ˚ı(ÍÓÏÔÎÂÍÒÌ˚ı) Í‚‡‰‡ÚÌ˚ı n × n χÚˈ, ÓÔ‰ÂÎÂÌ̇fl ͇Í|| A – B ||nat,„‰Â || ⋅ ||nat – ÂÒÚÂÒÚ‚ÂÌ̇fl ÌÓχ ̇ M n . ÖÒÚÂÒÚ‚ÂÌ̇fl ÌÓχ || ⋅ ||nat ̇ Mn ,ÔÓÓʉÂÌ̇fl ÌÓÏÓÈ ‚ÂÍÚÓ‡ || x ||^ x ∈ n (x ∈ n), ÂÒÚ¸ ÒÛ·ÏÛθÚËÔÎË͇Ú˂̇flÌÓχ χÚˈ˚, ÓÔ‰ÂÎÂÌ̇fl ͇Í|| Ax ||= sup || Ax ||= sup || Ax || .|| x || ≠ 0 || x |||| x || =1|| x || ≤1|| A |nat = supç‡ÚۇθÌÛ˛ ÏÂÚËÍÛ ÌÓÏ˚ ÏÓÊÌÓ Á‡‰‡Ú¸ ‡Ì‡Îӄ˘Ì˚Ï Ó·‡ÁÓÏ Ì‡ÏÌÓÊÂÒÚ‚Â M m,n ‚ÒÂı m × n ‰ÂÈÒÚ‚ËÚÂθÌ˚ı (ÍÓÏÔÎÂÍÒÌ˚ı) χÚˈ: ÂÒÎË Á‡‰‡Ì˚ÌÓÏ˚ ‚ÂÍÚÓ‡ ⋅ m ̇ m Ë ⋅ n ̇ n , ÂÒÚÂÒÚ‚ÂÌ̇fl ÌÓχ || A ||nat χÚˈ˚ A∈ Mm,n, ÔÓÓʉÂÌ̇fl ÌÓχÏË ⋅Í‡Í || A ||nat = supx n =1Axmm⋅Ën, ÂÒÚ¸ ÌÓχ χÚˈ˚, ÓÔ‰ÂÎÂÌ̇fl.åÂÚË͇ -ÌÓÏ˚ χÚˈ˚åÂÚË͇ -ÌÓÏ˚ χÚˈ˚ ̇Á˚‚‡ÂÚÒfl ̇Úۇθ̇fl ÏÂÚË͇ ÌÓÏ˚ ̇ Mn ,ÓÔ‰ÂÎÂÌ̇fl ͇Íp|| A − B ||nat,p„‰Â || ⋅ ||nat – -ÌÓχ χÚˈ˚, Ú.Â.
ÂÒÚÂÒÚ‚ÂÌ̇fl ÌÓχ, ÔÓÓʉÂÌ̇fl lp -ÌÓÏÓÈ‚ÂÍÚÓ‡, 1 ≤ p ≤ ∞:p|| A ||nat= max || Ax || p ,|| x || p =1„‰Â n|| x || p = | xi | p i =1∑1/ p.196ó‡ÒÚ¸ III. ê‡ÒÒÚÓflÌËfl ‚ Í·ÒÒ˘ÂÒÍÓÈ Ï‡ÚÂχÚËÍÂå‡ÍÒËχθÌÓÈ ‡·ÒÓβÚÌÓÈ ÏÂÚËÍÓÈ ÒÚÓηˆÓ‚ (ÚÓ˜ÌÂÂ, χÍÒËχθÌÓÈ ÏÂÚËÍÓÈ ÌÓÏ˚ ‡·ÒÓβÚÌ˚ı ÒÛÏÏ ÔÓ ÒÚÓηˆ‡Ï) fl‚ÎflÂÚÒfl ÏÂÚË͇ 1-ÌÓÏ˚ χÚˈ˚|| A − B ||1nat ̇ M n . 1-çÓχ χÚˈ˚ || ⋅ ||1nat , , ÔÓÓʉÂÌ̇fl l1 -ÌÓÏÓÈ ‚ÂÍÚÓ‡, ̇Á˚‚‡ÂÚÒfl Ú‡ÍÊ χÍÒËχθÌÓÈ ÌÓÏÓÈ ‡·ÒÓβÚÌ˚ı ÒÛÏÏ ÔÓ ÒÚÓηˆ‡Ï.ÑÎfl χÚˈ˚ A = ((aij)) ∈ Mn  ÏÓÊÌÓ Á‡ÔËÒ‡Ú¸ ͇Ín|| A ||1nat = max1≤ j ≤ n∑| aij | .i =1å‡ÍÒËχθÌÓÈ ‡·ÒÓβÚÌÓÈ ÏÂÚËÍÓÈ ÒÚÓÍ (ÚÓ˜ÌÂÂ, χÍÒËχθÌÓÈ ÏÂÚËÍÓÈÌÓÏ˚ ‡·ÒÓβÚÌ˚ı ÒÛÏÏ ÔÓ ÒÚÓ͇Ï) ̇Á˚‚‡ÂÚÒfl ÏÂÚË͇ -ÌÓÏ˚ χÚˈ˚|| A − B ||∞nat ̇ M n .
∞-çÓχ χÚˈ˚ || ⋅ ||∞nat , ÔÓÓʉÂÌ̇fl l ∞-ÌÓÏÓÈ ‚ÂÍÚÓ‡,̇Á˚‚‡ÂÚÒfl Ú‡ÍÊ χÍÒËχθÌÓÈ ÌÓÏÓÈ ‡·ÒÓβÚÌ˚ı ÒÛÏÏ ÔÓ ÒÚÓ͇Ï. ÑÎflχÚˈ˚ A = ((aij)) ∈ Mn  ÏÓÊÌÓ Á‡ÔËÒ‡Ú¸ ͇Í|| A ||∞nat = max1≤ j ≤ nn∑| aij | .j =1åÂÚË͇ ÒÔÂÍڇθÌÓÈ ÌÓÏ˚ – ˝ÚÓ ÏÂÚË͇ 2-ÌÓÏ˚ χÚˈ˚ || A − B ||2nat ̇ M n .ÑÎfl χÚˈ˚ A = ((aij)) ∈ Mn  ÏÓÊÌÓ Á‡ÔËÒ‡Ú¸ ͇Í|| A ||sp = (χÍÒËχθÌÓ ÒÓ·ÒÚ‚ÂÌÌÓ Á̇˜ÂÌË A* A)1/2,„‰Â χÚˈ‡ A∗ = (( aij ) ∈ Mn fl‚ÎflÂÚÒfl ÒÓÔflÊÂÌÌÓÈ Ú‡ÌÒÔÓÌËÓ‚‡ÌÌÓÈ Ï‡ÚˈÂÈχÚˈ˚ Ä (ÒÏ. åÂÚË͇ ÌÓÏ˚ äË î‡Ì‡, „Î. 14).åÂÚË͇ ÌÓÏ˚ îÓ·ÂÌËÛÒ‡åÂÚË͇ ÌÓÏ˚ îÓ·ÂÌËÛÒ‡ ÂÒÚ¸ ÏÂÚË͇ ÌÓÏ˚ χÚˈ˚ ̇ Mm,n, ÓÔ‰ÂÎÂÌ̇fl ͇Í|| A – B ||Fr,„‰Â || ⋅ ||Fr – ÌÓχ îÓ·ÂÌËÛÒ‡. ÑÎfl χÚˈ˚ A = ((aij)) ∈ Mm,n Ó̇ ÓÔ‰ÂÎflÂÚÒfl ͇Ímn∑∑|| A ||Fr =i =1| aij |2 .j =1é̇ ‡‚̇ Ú‡ÍÊ ͂‡‰‡ÚÌÓÏÛ ÍÓÌ˛ ËÁ ÒΉ‡ χÚˈ˚ A* A, „‰Â χÚˈ‡A = (( a ji )) fl‚ÎflÂÚÒfl ÒÓÔflÊÂÌÌÓÈ Ú‡ÌÒÔÓÌËÓ‚‡ÌÌÓÈ Ï‡ÚˈÂÈ ‰Îfl χÚˈ˚ ÄËÎË, ˝Í‚Ë‚‡ÎÂÌÚÌÓ, Í‚‡‰‡ÚÌÓÏÛ ÍÓÌ˛ ËÁ ÒÛÏÏ˚ ÒÓ·ÒÚ‚ÂÌÌ˚ı Á̇˜ÂÌËÈ λ i χÚ∗ˈ˚ A* A: || A ||Fr = Tr ( A∗ A) =min{m, n}∑λ i (ÒÏ.
åÂÚË͇ ÌÓÏ˚ ò‡ÚÂ̇, „Î. 13). ùÚ‡i =1ÌÓχ ÔÓÓʉÂ̇ Ò͇ÎflÌ˚Ï ÔÓËÁ‚‰ÂÌËÂÏ Ì‡ ÔÓÒÚ‡ÌÒÚ‚Â Mm,n, ÌÓ Ì fl‚ÎflÂÚÒflÒÛ·ÏÛθÚËÔÎË͇ÚË‚ÌÓÈ ‰Îfl m = n.åÂÚË͇ (c, p)-ÌÓÏ˚èÛÒÚ¸ k ∈ , k ≤ min{m, n}, c ∈ k, c 1 ≥ c 2 ≥ ⋅⋅⋅ ≥ ck > 0 Ë 1 ≤ p < ∞. åÂÚË͇ (c, p)ÌÓÏ˚ – ˝ÚÓ ÏÂÚË͇ ÌÓÏ˚ χÚˈ˚ ̇ M m,n, ÓÔ‰ÂÎÂÌ̇fl ͇Í|| A − B ||(kc, p ) ,197É·‚‡ 12. ê‡ÒÒÚÓflÌËfl ̇ ˜ËÒ·ı, ÏÌÓ„Ó˜ÎÂ̇ı Ë Ï‡Úˈ‡ı„‰Â || ⋅ ||(kc, p ) (c, p)-ÌÓχ ̇ M m,n. ÑÎfl χÚˈ˚ A ∈ Mm,n Ó̇ ÓÔ‰ÂÎflÂÚÒfl ͇Í||A ||(kc, p ) = kci sip ( A) i =1∑1/ p,„‰Â s1 (A) ≥ s2 (A) ≥ ⋅⋅⋅ ≥ sk(A) – Ô‚˚ k ÒËÌ„ÛÎflÌ˚ı Á̇˜ÂÌËÈ Ï‡Úˈ˚ Ä. ÖÒÎË p = 1,ÚÓ Ï˚ ÔÓÎÛ˜‡ÂÏ Ò-ÌÓÏÛ.