Download Perturbation Theory and Algebraic Equations with Examples | PHYS 6124 and more Study notes Physics in PDF only on Docsity! _Pectucbatoon Theory
Somakimes cannot RofI@ @ pooblem Cuaot bey , bet oan)
ele. tt appcovs ty a time ‘
shia. t Appcorimaseley, in @ Umut of smal C axge
paramokec (2), Often solutoon obtained Loe extcan
Small Vara & works rather well Loc wodecoke &,
Example:
We Exn4 =O, O64
Can sobve oxachhy 2 ya ck aNavee
Comacga, ef (e1<2 7
Teuncetad socteg _QNL Naky Qood approximatcon of the
Ask Tosukt, Tor 3% CLOUGH need
4 dace ~ leleoos
Q ate eee OY
Bar AR
Ant ee AS en re small: Catmost wear
cpmecaoneg boumetar ys \
Atgelcate Equatlons toa
How do we obtain an approximate anewar na Sy seamatic way ?
Expansion method
Repeesent Soliton as a Setiegin &8
WCE) = Wet ERATE KAS TK. Hey
ox Bes 2
aera YOER- 4 RO (2gavn).
2 2
Crt OK te Vag ye SOCK 4 SC a4 =
= (WP SEM KH KE LEK H gt) HC EMOt Byte) 4 =
= (KS 4S 4 22m TK) COTTA SO. Ae
> Pr -L eo => Ye et4
St, Qe sO => MLS *
Cry ZAM gtk, =O => Xa = may Coty? ya ad
—™ ~actdtes dette < cotnerdes Wath the expanse
of the React colbson “p to, 0 (<*)
Reautec perha'docion expansions AS Bo dolukton of tue
par tustoa A Ce oy poob Lenn PRCORONRE Uo Solution ot
Ae cenportucba dh Ce~o) gob Ler (245 x4 20)
Exowmp Sa 2 eee xX +4 =O
Pap)
Exack goleton: ya aN 4k, = ts Cn4es%e
Ze 227 2k
wm wc th (eee e ete) = [AT e-2ehs -
at Mie
BS gd?a 4 => S- 8% = yrhy-4=0
Da © A 4
ory 4 erat, tocye Senabh
Wo derms balancing Pay \
OS = £ > ex er-l =o
d & a a A
by 4 cena Darge Moke.
Domdmant balantear: %-t =O => *=44 < WoOdingulec
root &
Nop tat toca Ruletg
Coun wie days assume that the xoanslon X(E) cs. to Enbeqrar
Powers of e ?
Exompder: U-@>x*- 2x +4 =0
Foc GO + KR -Oet (a Cee no -S Kea l
a
ite Deganer acy — sign of tcoubte I
MEY = A+ EWE Kates
Qn=e)Cat Bx 4 Sea ceey te) +s
= G- edt 2EXp ao) = 2-2EK Hts
SHS AKOURZEK His HZ-22Kp rm +h HO
Se ane ai ao Lthose 44 =4 vorveckly
E's -4 42%,- 2%, = 0 ~ cannot be Sabiafesd tar Ay ons tee of X44
rong oxpan sion Y Loole. at The pansion of the arackroltis,,
ko con whet Werk won,’
y
te.
a
“(Ee = 2tN 4-4 (rey Aa oO iagtag te
TTee zy \-e
+ere..
Use <ascahing xe ttby tr Beye +dyy- 2A+by\ 44 = AA
a re Gree ory x (1-858? y* ~ 2 28y 4S
= -~e2-228y +Q-e)8%? =O
can appoxionaka Le with £ ty dong dorminant bakanoe:
gry 8ay)- 2 - E(B Ye - 8% -=0
a) SaaS => B= 8 => EY HE mK a
=O
4 “ No BALANCE!
coche emolR ox ad Cs
% bee => EY -2y ol =o -p Yao # 0
* a. & o
Large. Sirah srnalh \ Bo BALANCE! |
“ Mea => §=e% = yao Bo. ~4 =O
* *
Lorge Small ange.
Doosnan’ dolanag 2
y ~l=O0 = y= #4d
> R= Aaety = Ab Ee en
Appsoperake. Mx ponsion t xCe\= 44 exe BY, + OK bes
Eyecose 2 Bd Ky. ve by aquaking powets o aie
Tkevarine Mathod
Cigh+ Lxo aM ELON by sokvina tha Bq ation ibecariu the.
£ixS <0 oguivalent to y% = AON 4% EOD
Tkerate 2x4, = F Od?
Fexcad point of cherakion = Toeay ic acslitton ol £Oe\=0
. Ad,
Convergence of Aac dons Culd See again Un stability theory) 4
Can we Lind the Pixel point by therakeng ?
*
No Khe Veet ty of x S Xn = xP Bye x
Hu
ag a Bar = FOR = FOCHE) = FOF FOALS OE)
/ nh
2 Saag ODE, = FOS Say ee FON 8
Trecaktions, ComJerae iQ (elo <4
Note: Chalee of FOS ts nok unique, have. to choose Carefults
ho en®uce Comerar nee,
Notes Not every expansion is good, Look for txpan sions thet
COnVERER etl | > good okotee of yy te erthear |
ra
Excmp he:
H- 8) - 2x44 =0,
Rancike as exta x®
= A
=? Nnay = Ab 2x,
Stacking with x, =4¢
Example: ye =e
4
= eo “ Ee
y / NE g
y Kay > NN vo
Xp BS 2% =O 4 A se
eg
Yg= C27 = &
Mas feta C22 = C484 = yeti
D Kyar= Ont/ey~ Wns -%y = OnCve)
Maw Oacves «Bn Chal ved)
oxkcarnely alow by Convacaing ~