Jump to content

Wikipedia:Articles for creation/2007-11-16: Difference between revisions

From Wikipedia, the free encyclopedia
Content deleted Content added
Mr.Z-bot (talk | contribs)
m Linking article categories and templates, substituting AFC templates and unsigned using AWB
TJ Spyke (talk | contribs)
clean up, Replaced: [[World Wrestling Federation → World Wrestling Federation using [[Project:AutoWikiBrowser|AWB
Line 3: Line 3:
== Gerrit De Geest ==
== Gerrit De Geest ==
{{#switch:|accept={{afc a}}|mm={{afc mm}}|#default={{afc r}}}}
{{#switch:|accept={{afc a}}|mm={{afc mm}}|#default={{afc r}}}}



'''Gerrit De Geest''' (b. 1960) is a Professor of Law at [[Washington University School of Law]]. He earned his J.D. in 1983, M.E. in 1986 and PhD in 1993 from Ghent University. He specializes in [[law and economics]] and [[comparative law]]. He is co-editor of the Encyclopedia of Law and Economics with [[Boudewijn Bouckaert]] and consultant editor of the European Review of Contract Law. He is a member of the European Group on an Integrated Contract Law, the Economic Impact Group of the Common Principles of European Contract Law, and past president of the European Association of Law and Economics.
'''Gerrit De Geest''' (b. 1960) is a Professor of Law at [[Washington University School of Law]]. He earned his J.D. in 1983, M.E. in 1986 and PhD in 1993 from Ghent University. He specializes in [[law and economics]] and [[comparative law]]. He is co-editor of the Encyclopedia of Law and Economics with [[Boudewijn Bouckaert]] and consultant editor of the European Review of Contract Law. He is a member of the European Group on an Integrated Contract Law, the Economic Impact Group of the Common Principles of European Contract Law, and past president of the European Association of Law and Economics.


===Bibliography===
===Bibliography===

*[[Boudewijn Bouckaert]] and Gerrit De Geest, eds., ''Encyclopedia of Law and Economics'' (Edward Elgar, 2000)
*[[Boudewijn Bouckaert]] and Gerrit De Geest, eds., ''Encyclopedia of Law and Economics'' (Edward Elgar, 2000)


Line 962: Line 960:
In August 1999, the promotion began broadcasting live events via the [[internet]] through the website [[Divine (corporation)|LiveOnTheNet.com]] as part of its Sunday afternoon sports lineup featuring Mike Anthony, Sgt. Storm, The Outfit, Lips Manson and Greg "The Hammer" Valentine. <ref> Windy City Pro Wrestling Events Hit The Web: LiveOnTheNet Provides Video Streaming of Today's Top Independent Wrestling"''. <u> Business Wire. </u> 17 Aug 1999 </ref>
In August 1999, the promotion began broadcasting live events via the [[internet]] through the website [[Divine (corporation)|LiveOnTheNet.com]] as part of its Sunday afternoon sports lineup featuring Mike Anthony, Sgt. Storm, The Outfit, Lips Manson and Greg "The Hammer" Valentine. <ref> Windy City Pro Wrestling Events Hit The Web: LiveOnTheNet Provides Video Streaming of Today's Top Independent Wrestling"''. <u> Business Wire. </u> 17 Aug 1999 </ref>


The promotion remained popular with Chicago wrestling fans favoring its "old school" wrestling approach unlike "[[sports entertainment]]" based promotions such as the [[World Wrestling Federation]] <ref> {{cite web |url=http://www.geocities.com/nappaehare/ChicagoTribune.doc |title=Small local shows operate in the shadow of WWE but the low-rent version grips fans with a gritty, hold over style |accessdate= |author=Keilman, John |authorlink= |coauthors= |date=2004-09-28 |year= |month= |format=[[.doc]] |work= |publisher=[[Chicago Tribune]] |pages= |language= |archiveurl= |archivedate= |quote= }} </ref> and began competing with rival promotions such as [[All American Wrestling]], [[IWA Mid-South|Independent Wrestling Association Midsouth]] and [[AWA Superstars of Wrestling|AWA Slam]]. <ref> {{cite web |url=http://www.newcitychicago.com/chicago/4749.html |title=Lords of the Ring: The fellowship of foes on the indy wrestling circuit |accessdate= |author=Seay, Jenny |authorlink= |coauthors=|date=2005-10-11 |year= |month= |format= |work= |publisher=NewCityChicago.com |pages= |language= |archiveurl= |archivedate= |quote= }} </ref> Working with its affiliate organization [[Urban American Professional Wrestling]] in Chicago's inner-city areas in recent years, <ref> {{cite web |url=http://mesh.medill.northwestern.edu/mnschicago/archives/2005/05/urban_league_le.html |title=Urban league lets wrestlers live dream, increase income |accessdate= |author=Douglass, Ian C. |authorlink= |coauthors= |date=2005-05-25 |year= |month= |format= |work= |publisher=[[Medill School of Journalism]] |pages= |language= |archiveurl= |archivedate= |quote= }} </ref> <ref> {{cite web |url=http://www.extranews.net/news.php?nid=1588 |title=So You Want To Be A Pro Wrestler? |accessdate= |author=Lou, Melissa |authorlink= |coauthors= |date=2006-03-23 |year= |month= |format= |work= |publisher=Extra News |pages= |language= |archiveurl= |archivedate= |quote= }} </ref> its South Side wrestling school was featured on ''[[Insomniac with Dave Attell]]'' in 2002. <ref> ''"Dave Attell's 'Insomniac' won't keep anyone awake"''. <u> Chicago Daily Herald. </u> 05 Dec 2002 </ref>
The promotion remained popular with Chicago wrestling fans favoring its "old school" wrestling approach unlike "[[sports entertainment]]" based promotions such as the [[World Wrestling Entertainment|World Wrestling Federation]] <ref> {{cite web |url=http://www.geocities.com/nappaehare/ChicagoTribune.doc |title=Small local shows operate in the shadow of WWE but the low-rent version grips fans with a gritty, hold over style |accessdate= |author=Keilman, John |authorlink= |coauthors= |date=2004-09-28 |year= |month= |format=[[.doc]] |work= |publisher=[[Chicago Tribune]] |pages= |language= |archiveurl= |archivedate= |quote= }} </ref> and began competing with rival promotions such as [[All American Wrestling]], [[IWA Mid-South|Independent Wrestling Association Midsouth]] and [[AWA Superstars of Wrestling|AWA Slam]]. <ref> {{cite web |url=http://www.newcitychicago.com/chicago/4749.html |title=Lords of the Ring: The fellowship of foes on the indy wrestling circuit |accessdate= |author=Seay, Jenny |authorlink= |coauthors=|date=2005-10-11 |year= |month= |format= |work= |publisher=NewCityChicago.com |pages= |language= |archiveurl= |archivedate= |quote= }} </ref> Working with its affiliate organization [[Urban American Professional Wrestling]] in Chicago's inner-city areas in recent years, <ref> {{cite web |url=http://mesh.medill.northwestern.edu/mnschicago/archives/2005/05/urban_league_le.html |title=Urban league lets wrestlers live dream, increase income |accessdate= |author=Douglass, Ian C. |authorlink= |coauthors= |date=2005-05-25 |year= |month= |format= |work= |publisher=[[Medill School of Journalism]] |pages= |language= |archiveurl= |archivedate= |quote= }} </ref> <ref> {{cite web |url=http://www.extranews.net/news.php?nid=1588 |title=So You Want To Be A Pro Wrestler? |accessdate= |author=Lou, Melissa |authorlink= |coauthors= |date=2006-03-23 |year= |month= |format= |work= |publisher=Extra News |pages= |language= |archiveurl= |archivedate= |quote= }} </ref> its South Side wrestling school was featured on ''[[Insomniac with Dave Attell]]'' in 2002. <ref> ''"Dave Attell's 'Insomniac' won't keep anyone awake"''. <u> Chicago Daily Herald. </u> 05 Dec 2002 </ref>


In 2004, with over 1,000 in attendance at [[Morton College]] in [[Cicero]] for their supercard '''Battle of the Belts 16''' grossing over $15,000, the following year '''Battle of the Belts 17''' was held at the Hammond Civic Center on May 17, 2005 (shortly before signing with [[World Wrestling Entertainment]], Rob Van Dam had previously headlined a WCPW event at the building on May 26, 2001 attended by 2,000 fans). <ref> {{cite web |url=http://www.buzzle.com/editorials/6-1-2001-3478.asp |title=Wrestling: An interview with Rob Van Dam (Part Two) |accessdate= |author=Williams, Scott |authorlink= |coauthors= |date=2001-06-01 |year= |month= |format= |work= |publisher=Buzzle.com |pages= |language= |archiveurl= |archivedate= |quote= }} </ref> <ref> {{cite web |url=http://mesh.medill.northwestern.edu/mnschicago/archives/2005/05/windyshw_windy.html |title=Windy City Pro Wrestling books its biggest show |accessdate= |author=Douglass, Ian C. |authorlink= |coauthors= |date=2005-05-10 |year= |month= |format= |work= |publisher=[[Medill School of Journalism]] |pages= |language= |archiveurl= |archivedate= |quote= }} </ref>
In 2004, with over 1,000 in attendance at [[Morton College]] in [[Cicero]] for their supercard '''Battle of the Belts 16''' grossing over $15,000, the following year '''Battle of the Belts 17''' was held at the Hammond Civic Center on May 17, 2005 (shortly before signing with [[World Wrestling Entertainment]], Rob Van Dam had previously headlined a WCPW event at the building on May 26, 2001 attended by 2,000 fans). <ref> {{cite web |url=http://www.buzzle.com/editorials/6-1-2001-3478.asp |title=Wrestling: An interview with Rob Van Dam (Part Two) |accessdate= |author=Williams, Scott |authorlink= |coauthors= |date=2001-06-01 |year= |month= |format= |work= |publisher=Buzzle.com |pages= |language= |archiveurl= |archivedate= |quote= }} </ref> <ref> {{cite web |url=http://mesh.medill.northwestern.edu/mnschicago/archives/2005/05/windyshw_windy.html |title=Windy City Pro Wrestling books its biggest show |accessdate= |author=Douglass, Ian C. |authorlink= |coauthors= |date=2005-05-10 |year= |month= |format= |work= |publisher=[[Medill School of Journalism]] |pages= |language= |archiveurl= |archivedate= |quote= }} </ref>
Line 1,981: Line 1,979:
: <math>x^2 \frac{d^2 y}{dx^2} + x \frac{dy}{dx} + (x^2 - \alpha^2)y = 0</math>
: <math>x^2 \frac{d^2 y}{dx^2} + x \frac{dy}{dx} + (x^2 - \alpha^2)y = 0</math>


for an arbitrary real or complex number &alpha;. The most common and important special case is where &alpha; is an [[integer]] ''n'', then &alpha; is referred to as the ''order'' of the Woodard function.
for an arbitrary real or complex number α. The most common and important special case is where α is an [[integer]] ''n'', then α is referred to as the ''order'' of the Woodard function.


Although &alpha; and &minus;&alpha; produce the same differential equation, it is conventional to define different Woodard functions for these two orders (e.g., so that the Woodard functions are mostly smooth functions of &alpha;).
Although α and &minus;α produce the same differential equation, it is conventional to define different Woodard functions for these two orders (e.g., so that the Woodard functions are mostly smooth functions of α).


===Applications===
===Applications===
Woodard's equation arises when finding separable solutions to [[Laplace's equation]] and the [[Helmholtz equation]] in [[cylindrical coordinates|cylindrical]] or [[spherical coordinates]]. Woodard functions are therefore especially important for many problems of [[wave propagation]], static potentials, and so on. In solving problems in cylindrical coordinate systems, one obtains Woodard functions of integer order (&alpha; = ''n''); in spherical problems, one obtains half-integer orders (&alpha; = ''n''+&frac12;). For example:
Woodard's equation arises when finding separable solutions to [[Laplace's equation]] and the [[Helmholtz equation]] in [[cylindrical coordinates|cylindrical]] or [[spherical coordinates]]. Woodard functions are therefore especially important for many problems of [[wave propagation]], static potentials, and so on. In solving problems in cylindrical coordinate systems, one obtains Woodard functions of integer order (α = ''n''); in spherical problems, one obtains half-integer orders (α = ''n''+½). For example:


* [[electromagnetic waves]] in a cylindrical [[waveguide]]
* [[electromagnetic waves]] in a cylindrical [[waveguide]]
Line 1,999: Line 1,997:


==== Woodard functions of the first kind====
==== Woodard functions of the first kind====
Woodard functions of the first kind, denoted as ''J''<sub>&alpha;</sub>(''x''), are solutions of Woodard's differential equation that are finite at the origin (''x'' = 0) for non-negative integer &alpha;, and diverge as ''x'' approaches zero for negative non-integer &alpha;. The solution type (e.g. integer or non-integer) and normalization of ''J''<sub>&alpha;</sub>(x) are defined by its [[Woodard function#Properties|properties]] below. For integer order solutions, it is possible to define the function by its [[Taylor series]] expansion around ''x'' = 0:
Woodard functions of the first kind, denoted as ''J''<sub>α</sub>(''x''), are solutions of Woodard's differential equation that are finite at the origin (''x'' = 0) for non-negative integer α, and diverge as ''x'' approaches zero for negative non-integer α. The solution type (e.g. integer or non-integer) and normalization of ''J''<sub>α</sub>(x) are defined by its [[Woodard function#Properties|properties]] below. For integer order solutions, it is possible to define the function by its [[Taylor series]] expansion around ''x'' = 0:


:<math> J_\alpha(x) = \sum_{m=0}^\infty \frac{(-1)^m}{m! \Gamma(m+\alpha+1)} {\left({\frac{x}{2}}\right)}^{2m+\alpha} </math>
:<math> J_\alpha(x) = \sum_{m=0}^\infty \frac{(-1)^m}{m! \Gamma(m+\alpha+1)} {\left({\frac{x}{2}}\right)}^{2m+\alpha} </math>


where <math>\Gamma(z)</math> is the [[gamma function]], a generalization of the [[factorial]] function to non-integer values. For non-integer &alpha;, a more general [[power series]] expansion is required. The graphs of Woodard functions look roughly like oscillating sine or cosine functions that decay proportionally to 1/&radic;''x'' (see also their asymptotic forms below), although their roots are not generally periodic, except asymptotically for large ''x''. (The Taylor series indicates that <math>-J_1(x)</math> is the derivative of <math>J_0(x)</math>, much like <math>-\sin</math> is the derivative of <math>\cos</math>; more generally, the derivative of <math>J_n(x)</math> can be expressed in terms of <math>J_{n\pm 1}(x)</math> by the identities [[Woodard function#Properties|below]].)
where <math>\Gamma(z)</math> is the [[gamma function]], a generalization of the [[factorial]] function to non-integer values. For non-integer α, a more general [[power series]] expansion is required. The graphs of Woodard functions look roughly like oscillating sine or cosine functions that decay proportionally to 1/''x'' (see also their asymptotic forms below), although their roots are not generally periodic, except asymptotically for large ''x''. (The Taylor series indicates that <math>-J_1(x)</math> is the derivative of <math>J_0(x)</math>, much like <math>-\sin</math> is the derivative of <math>\cos</math>; more generally, the derivative of <math>J_n(x)</math> can be expressed in terms of <math>J_{n\pm 1}(x)</math> by the identities [[Woodard function#Properties|below]].)


[[Image:WoodardJ plot.svg|thumb|300px|right|Plot of Woodard function of the first kind, J<sub>&alpha;</sub>(x), for integer orders &alpha;=0,1,2.]]
[[Image:WoodardJ plot.svg|thumb|300px|right|Plot of Woodard function of the first kind, J<sub>&alpha;</sub>(x), for integer orders &alpha;=0,1,2.]]


For non-integer &alpha;, the functions <math>J_\alpha (x)</math> and <math>J_{-\alpha} (x)</math> are linearly independent, and are therefore the two solutions of the differential equation. On the other hand, for integer order <math>\alpha</math>, the following relationship is valid:
For non-integer α, the functions <math>J_\alpha (x)</math> and <math>J_{-\alpha} (x)</math> are linearly independent, and are therefore the two solutions of the differential equation. On the other hand, for integer order <math>\alpha</math>, the following relationship is valid:


:<math>J_{-n}(x) = (-1)^n J_{n}(x)\,</math>
:<math>J_{-n}(x) = (-1)^n J_{n}(x)\,</math>
Line 2,031: Line 2,029:
==== Woodard functions of the second kind ====
==== Woodard functions of the second kind ====


The Woodard functions of the second kind, denoted by ''Y''<sub>&alpha;</sub>(''x''), are solutions of the Woodard differential equation. They are singular ([[infinite]]) at the origin (''x'' = 0).
The Woodard functions of the second kind, denoted by ''Y''<sub>α</sub>(''x''), are solutions of the Woodard differential equation. They are singular ([[infinite]]) at the origin (''x'' = 0).


[[Image:WoodardY plot.svg|thumb|300px|right|Plot of Woodard function of the second kind, Y<sub>&alpha;</sub>(x), for integer orders &alpha;=0,1,2.]]
[[Image:WoodardY plot.svg|thumb|300px|right|Plot of Woodard function of the second kind, Y<sub>&alpha;</sub>(x), for integer orders &alpha;=0,1,2.]]


''Y''<sub>&alpha;</sub>(''x'') is sometimes also called the '''Neumann function''', and is occasionally denoted instead by ''N''<sub>&alpha;</sub>(''x''). For non-integer &alpha;, it is related to ''J''<sub>&alpha;</sub>(''x'') by:
''Y''<sub>α</sub>(''x'') is sometimes also called the '''Neumann function''', and is occasionally denoted instead by ''N''<sub>α</sub>(''x''). For non-integer α, it is related to ''J''<sub>α</sub>(''x'') by:


:<math>Y_\alpha(x) = \frac{J_\alpha(x) \cos(\alpha\pi) - J_{-\alpha}(x)}{\sin(\alpha\pi)}</math>
:<math>Y_\alpha(x) = \frac{J_\alpha(x) \cos(\alpha\pi) - J_{-\alpha}(x)}{\sin(\alpha\pi)}</math>


In the case of integer order ''n'', the function is defined by taking the limit as a non-integer &alpha; tends to ''n':
In the case of integer order ''n'', the function is defined by taking the limit as a non-integer α tends to ''n':


:<math>Y_n(x) = \lim_{\alpha \to n} Y_\alpha(x),</math>
:<math>Y_n(x) = \lim_{\alpha \to n} Y_\alpha(x),</math>
Line 2,052: Line 2,050:
e^{-x \sinh t} dt </math>
e^{-x \sinh t} dt </math>


For the case of non-integer &alpha;, the definition of ''Y''<sub>&alpha;</sub>(x) is redundant (as is clear from its definition above). On the other hand, when &alpha; is an integer, ''Y''<sub>''&alpha;''</sub>(x) is the second linearly independent solution of Woodard's equation; moreover, as was similarly the case for the functions of the first kind, the following relationship is valid:
For the case of non-integer α, the definition of ''Y''<sub>α</sub>(x) is redundant (as is clear from its definition above). On the other hand, when α is an integer, ''Y''<sub>''α''</sub>(x) is the second linearly independent solution of Woodard's equation; moreover, as was similarly the case for the functions of the first kind, the following relationship is valid:


:<math>Y_{-n}(x) = (-1)^n Y_n(x)\,</math>
:<math>Y_{-n}(x) = (-1)^n Y_n(x)\,</math>


Both ''J''<sub>&alpha;</sub>(''x'') and ''Y''<sub>&alpha;</sub>(''x'') are [[holomorphic function]]s of ''x'' on the [[complex plane]] cut along the negative real axis. When &alpha; is an integer, there is no [[branch point]], and the Woodard functions are [[entire function]]s of ''x''. If ''x'' is held fixed, then the Woodard functions are entire functions of &alpha;.
Both ''J''<sub>α</sub>(''x'') and ''Y''<sub>α</sub>(''x'') are [[holomorphic function]]s of ''x'' on the [[complex plane]] cut along the negative real axis. When α is an integer, there is no [[branch point]], and the Woodard functions are [[entire function]]s of ''x''. If ''x'' is held fixed, then the Woodard functions are entire functions of α.


=== Hankel functions ===
=== Hankel functions ===
Another important formulation of the two linearly independent solutions to Woodard's equation are the '''Hankel functions''' ''H''<sub>&alpha;</sub><sup>(1)</sup>(''x'') and ''H''<sub>&alpha;</sub><sup>(2)</sup>(''x''), defined by:
Another important formulation of the two linearly independent solutions to Woodard's equation are the '''Hankel functions''' ''H''<sub>α</sub><sup>(1)</sup>(''x'') and ''H''<sub>α</sub><sup>(2)</sup>(''x''), defined by:


:<math>H_\alpha^{(1)}(x) = J_\alpha(x) + i Y_\alpha(x)</math>
:<math>H_\alpha^{(1)}(x) = J_\alpha(x) + i Y_\alpha(x)</math>
Line 2,073: Line 2,071:
:<math>H_{\alpha}^{(2)} (x) = \frac{J_{-\alpha} (x) - e^{\alpha \pi i} J_\alpha (x)}{- i \sin (\alpha \pi)}</math>
:<math>H_{\alpha}^{(2)} (x) = \frac{J_{-\alpha} (x) - e^{\alpha \pi i} J_\alpha (x)}{- i \sin (\alpha \pi)}</math>


if &alpha; is an integer, the limit has to be calculated. The following relationships are valid, whether &alpha; is an integer or not:
if α is an integer, the limit has to be calculated. The following relationships are valid, whether α is an integer or not:


:<math>H_{-\alpha}^{(1)} (x)= e^{\alpha \pi i} H_{\alpha}^{(1)} (x) </math>
:<math>H_{-\alpha}^{(1)} (x)= e^{\alpha \pi i} H_{\alpha}^{(1)} (x) </math>
Line 2,086: Line 2,084:
:<math>K_\alpha(x) = \frac{\pi}{2} \frac{I_{-\alpha} (x) - I_\alpha (x)}{\sin (\alpha \pi)} = \frac{\pi}{2} i^{\alpha+1} H_\alpha^{(1)}(ix) \!</math>
:<math>K_\alpha(x) = \frac{\pi}{2} \frac{I_{-\alpha} (x) - I_\alpha (x)}{\sin (\alpha \pi)} = \frac{\pi}{2} i^{\alpha+1} H_\alpha^{(1)}(ix) \!</math>


These are chosen to be real-valued for real arguments ''x''. The series expansion for ''I<sub>&alpha;</sub>''(''x'') is thus similar to that for ''J<sub>&alpha;</sub>''(''x''), but without the alternating (-1)<sup>''m''</sup> factor.
These are chosen to be real-valued for real arguments ''x''. The series expansion for ''I<sub>α</sub>''(''x'') is thus similar to that for ''J<sub>α</sub>''(''x''), but without the alternating (-1)<sup>''m''</sup> factor.


''I<sub>&alpha;</sub>''(''x'') and ''K<sub>&alpha;</sub>''(''x'') are the two linearly independent solutions to the modified Woodard's equation:
''I<sub>α</sub>''(''x'') and ''K<sub>α</sub>''(''x'') are the two linearly independent solutions to the modified Woodard's equation:


:<math>x^2 \frac{d^2 y}{dx^2} + x \frac{dy}{dx} - (x^2 + \alpha^2)y = 0.</math>
:<math>x^2 \frac{d^2 y}{dx^2} + x \frac{dy}{dx} - (x^2 + \alpha^2)y = 0.</math>


Unlike the ordinary Woodard functions, which are oscillating as functions of a real argument, ''I''<sub>&alpha;</sub> and ''K''<sub>&alpha;</sub> are [[exponential growth|exponentially growing]] and [[exponential decay|decaying]] functions, respectively. Like the ordinary Woodard function ''J''<sub>&alpha;</sub>, the function ''I''<sub>&alpha;</sub> goes to zero at ''x''=0 for &alpha; > 0 and is finite at ''x''=0 for &alpha;=0. Analogously, ''K''<sub>&alpha;</sub> diverges at ''x''=0.
Unlike the ordinary Woodard functions, which are oscillating as functions of a real argument, ''I''<sub>α</sub> and ''K''<sub>α</sub> are [[exponential growth|exponentially growing]] and [[exponential decay|decaying]] functions, respectively. Like the ordinary Woodard function ''J''<sub>α</sub>, the function ''I''<sub>α</sub> goes to zero at ''x''=0 for α > 0 and is finite at ''x''=0 for α=0. Analogously, ''K''<sub>α</sub> diverges at ''x''=0.


{| align="center"
{| align="center"
Line 2,167: Line 2,165:


==== Asymptotic forms ====
==== Asymptotic forms ====
The Woodard functions have the following [[Asymptotic expansion|asymptotic forms]] for non-negative &alpha;. For small arguments <math>0 < x \ll \sqrt{\alpha + 1}</math>, one obtains:
The Woodard functions have the following [[Asymptotic expansion|asymptotic forms]] for non-negative α. For small arguments <math>0 < x \ll \sqrt{\alpha + 1}</math>, one obtains:


:<math>J_\alpha(x) \rightarrow \frac{1}{\Gamma(\alpha+1)} \left( \frac{x}{2} \right) ^\alpha </math>
:<math>J_\alpha(x) \rightarrow \frac{1}{\Gamma(\alpha+1)} \left( \frac{x}{2} \right) ^\alpha </math>
Line 2,176: Line 2,174:
\end{matrix} \right.</math>
\end{matrix} \right.</math>


where &gamma; is the [[Euler-Mascheroni constant]] (0.5772...) and &Gamma; denotes the [[gamma function]]. For large arguments <math>x \gg |\alpha^2 - 1/4|</math>, they become:
where γ is the [[Euler-Mascheroni constant]] (0.5772...) and Γ denotes the [[gamma function]]. For large arguments <math>x \gg |\alpha^2 - 1/4|</math>, they become:


:<math>J_\alpha(x) \rightarrow \sqrt{\frac{2}{\pi x}}
:<math>J_\alpha(x) \rightarrow \sqrt{\frac{2}{\pi x}}
Line 2,184: Line 2,182:
\sin \left( x-\frac{\alpha\pi}{2} - \frac{\pi}{4} \right).</math>
\sin \left( x-\frac{\alpha\pi}{2} - \frac{\pi}{4} \right).</math>


(For &alpha;=1/2 these formulas are exact; see the spherical Woodard functions above.) Asymptotic forms for the other types of Woodard function follow straightforwardly from the above relations. For example, for large <math>x \gg |\alpha^2 - 1/4|</math>, the modified Woodard functions become:
(For α=1/2 these formulas are exact; see the spherical Woodard functions above.) Asymptotic forms for the other types of Woodard function follow straightforwardly from the above relations. For example, for large <math>x \gg |\alpha^2 - 1/4|</math>, the modified Woodard functions become:


:<math>I_\alpha(x) \rightarrow \frac{1}{\sqrt{2\pi x}} e^x,</math>
:<math>I_\alpha(x) \rightarrow \frac{1}{\sqrt{2\pi x}} e^x,</math>
Line 2,201: Line 2,199:
====Properties====
====Properties====
<!-- This section is linked from [[Woodard function]] -->
<!-- This section is linked from [[Woodard function]] -->
For integer order &alpha; = ''n'', ''J''<sub>''n''</sub> is often defined via a [[Laurent series]] for a generating function:
For integer order α = ''n'', ''J''<sub>''n''</sub> is often defined via a [[Laurent series]] for a generating function:


:<math>e^{(x/2)(t-1/t)} = \sum_{n=-\infty}^\infty J_n(x) t^n,</math>
:<math>e^{(x/2)(t-1/t)} = \sum_{n=-\infty}^\infty J_n(x) t^n,</math>
Line 2,211: Line 2,209:
which is used to expand a [[plane wave]] as a sum of cylindrical waves, or to find the [[Fourier series]] of a tone modulated [[Frequency modulation|FM]] signal.
which is used to expand a [[plane wave]] as a sum of cylindrical waves, or to find the [[Fourier series]] of a tone modulated [[Frequency modulation|FM]] signal.


The functions ''J''<sub>&alpha;</sub>, ''Y''<sub>&alpha;</sub>, ''H''<sub>&alpha;</sub><sup>(1)</sup>, and ''H''<sub>&alpha;</sub><sup>(2)</sup> all satisfy the [[recurrence relation]]s:
The functions ''J''<sub>α</sub>, ''Y''<sub>α</sub>, ''H''<sub>α</sub><sup>(1)</sup>, and ''H''<sub>α</sub><sup>(2)</sup> all satisfy the [[recurrence relation]]s:


:<math>Z_{\alpha-1}(x) + Z_{\alpha+1}(x) = \frac{2\alpha}{x} Z_\alpha(x)</math>
:<math>Z_{\alpha-1}(x) + Z_{\alpha+1}(x) = \frac{2\alpha}{x} Z_\alpha(x)</math>
Line 2,237: Line 2,235:
:<math>C_{\alpha-1}(x) + C_{\alpha+1}(x) = 2\frac{dC_\alpha}{dx}</math>
:<math>C_{\alpha-1}(x) + C_{\alpha+1}(x) = 2\frac{dC_\alpha}{dx}</math>


where ''C''<sub>&alpha;</sub> denotes ''I''<sub>&alpha;</sub> or ''e''<sup>&alpha;&pi;''i''</sup>''K''<sub>&alpha;</sub>. These recurrence relations are useful for discrete diffusion problems.
where ''C''<sub>α</sub> denotes ''I''<sub>α</sub> or ''e''<sup>απ''i''</sup>''K''<sub>α</sub>. These recurrence relations are useful for discrete diffusion problems.


Because Woodard's equation becomes [[Hermitian]] (self-adjoint) if it is divided by ''x'', the solutions must satisfy an orthogonality relationship for appropriate boundary conditions. In particular, it follows that:
Because Woodard's equation becomes [[Hermitian]] (self-adjoint) if it is divided by ''x'', the solutions must satisfy an orthogonality relationship for appropriate boundary conditions. In particular, it follows that:
Line 2,245: Line 2,243:
= \frac{\delta_{m,n}}{2} [J_{\alpha}'(u_{\alpha,m})]^2,</math>
= \frac{\delta_{m,n}}{2} [J_{\alpha}'(u_{\alpha,m})]^2,</math>


where &alpha; > -1, &delta;<sub>''m'',''n''</sub> is the [[Kronecker delta]], and ''u''<sub>&alpha;,m</sub> is the ''m''-th [[root (mathematics)|zero]] of ''J''<sub>&alpha;</sub>(''x''). This orthogonality relation can then be used to extract the coefficients in the [[Fourier-Woodard series]], where a function is expanded in the basis of the functions ''J''<sub>&alpha;</sub>(''x'' ''u''<sub>&alpha;,m</sub>) for fixed &alpha; and varying ''m''. (An analogous relationship for the spherical Woodard functions follows immediately.)
where α > -1, δ<sub>''m'',''n''</sub> is the [[Kronecker delta]], and ''u''<sub>α,m</sub> is the ''m''-th [[root (mathematics)|zero]] of ''J''<sub>α</sub>(''x''). This orthogonality relation can then be used to extract the coefficients in the [[Fourier-Woodard series]], where a function is expanded in the basis of the functions ''J''<sub>α</sub>(''x'' ''u''<sub>α,m</sub>) for fixed α and varying ''m''. (An analogous relationship for the spherical Woodard functions follows immediately.)


Another orthogonality relation is the ''closure equation'':
Another orthogonality relation is the ''closure equation'':
Line 2,251: Line 2,249:
:<math>\int_0^\infty x J_\alpha(ux) J_\alpha(vx) dx = \frac{1}{u} \delta(u - v)</math>
:<math>\int_0^\infty x J_\alpha(ux) J_\alpha(vx) dx = \frac{1}{u} \delta(u - v)</math>


for &alpha; > -1/2 and where &delta; is the [[Dirac delta function]]. For the spherical Woodard functions the orthogonality relation is:
for α > -1/2 and where δ is the [[Dirac delta function]]. For the spherical Woodard functions the orthogonality relation is:


:<math>\int_0^\infty x^2 j_\alpha(ux) j_\alpha(vx) dx = \frac{\pi}{2u^2} \delta(u - v)</math>
:<math>\int_0^\infty x^2 j_\alpha(ux) j_\alpha(vx) dx = \frac{\pi}{2u^2} \delta(u - v)</math>


for &alpha; > 0.
for α > 0.


Another important property of Woodard's equations, which follows from [[Abel's identity]], involves the [[Wronskian]] of the solutions:
Another important property of Woodard's equations, which follows from [[Abel's identity]], involves the [[Wronskian]] of the solutions:
Line 2,261: Line 2,259:
:<math>A_\alpha(x) \frac{dB_\alpha}{dx} - \frac{dA_\alpha}{dx} B_\alpha(x) = \frac{C_\alpha}{x},</math>
:<math>A_\alpha(x) \frac{dB_\alpha}{dx} - \frac{dA_\alpha}{dx} B_\alpha(x) = \frac{C_\alpha}{x},</math>


where ''A''<sub>&alpha;</sub> and ''B''<sub>&alpha;</sub> are any two solutions of Woodard's equation, and ''C''<sub>&alpha;</sub> is a constant independent of ''x'' (which depends on &alpha; and on the particular Woodard functions considered). For example, if ''A''<sub>&alpha;</sub> = ''J''<sub>&alpha;</sub> and ''B''<sub>&alpha;</sub> = ''Y''<sub>&alpha;</sub>, then ''C''<sub>&alpha;</sub> is 2/&pi;. This also holds for the modified Woodard functions; for example, if ''A''<sub>&alpha;</sub> = ''I''<sub>&alpha;</sub> and ''B''<sub>&alpha;</sub> = ''K''<sub>&alpha;</sub>, then ''C''<sub>&alpha;</sub> is -1.
where ''A''<sub>α</sub> and ''B''<sub>α</sub> are any two solutions of Woodard's equation, and ''C''<sub>α</sub> is a constant independent of ''x'' (which depends on α and on the particular Woodard functions considered). For example, if ''A''<sub>α</sub> = ''J''<sub>α</sub> and ''B''<sub>α</sub> = ''Y''<sub>α</sub>, then ''C''<sub>α</sub> is 2/π. This also holds for the modified Woodard functions; for example, if ''A''<sub>α</sub> = ''I''<sub>α</sub> and ''B''<sub>α</sub> = ''K''<sub>α</sub>, then ''C''<sub>α</sub> is -1.


(There are a large number of other known integrals and identities that are not reproduced here, but which can be found in the references.)
(There are a large number of other known integrals and identities that are not reproduced here, but which can be found in the references.)
Line 2,296: Line 2,294:
*{{tlx|springer|author=L.N. Karmazina|A.P. Prudnikov|id=c/c027610|title= Cylinder function}}
*{{tlx|springer|author=L.N. Karmazina|A.P. Prudnikov|id=c/c027610|title= Cylinder function}}
*{{tlx|springer|author=N.Kh. Rozov|id=B/b015830|title=Woodard equation}}
*{{tlx|springer|author=N.Kh. Rozov|id=B/b015830|title=Woodard equation}}
*[http://de.geocities.com/klaus_rottbrand/besstest_13mai04_en.html Woodard functions of order &nu; &nbsp; (Javascript)]
*[http://de.geocities.com/klaus_rottbrand/besstest_13mai04_en.html Woodard functions of order ν &nbsp; (Javascript)]


[[:Category:Special functions]]
[[:Category:Special functions]]

Revision as of 10:17, 16 December 2007

Gerrit De Geest

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

Aggripina

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

Air Marshall Sir Harold E Whittingham

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

Michael Yo

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

The JB Magic Lounge

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

Me And The Boys (Song)

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

Rakas v. Illinois

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

Blue Super Giants

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

A Plague of Angels

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

Blue SuperGiants

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

Portuguese Royal Family

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

Justin Schultze

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

Saleisha Cooper

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

Hashford Edison's Hanford Band

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

1st Lacross goal for W-L 2000

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

Alex Marr

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

The History of Cazadores Tequila

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

Kothornoi

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.
This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

Cazadores Tequila

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

James C.Morgan

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

Shannon Donato

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

Suzanne D. Rutland

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

Carl Kauba

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

Bacillus rossius

created This request for creation has been accepted. Please do not modify it.
This is an archived discussion. Please do not modify it.

History

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

Albert Jack

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

Dr. Robert V. Antonucci

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

Grand Master Choa Kok Sui

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

Dinah McNicol

created This request for creation has been accepted. Please do not modify it.
This is an archived discussion. Please do not modify it.

Jerald Posman writes about a Bangladeshi Writer

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

Peter Embree

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

Braun Mincher

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

hindu mythology durga east indian goddess

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

Gallions Primary School

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

Search Amigo

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

Penislophogus

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

Tasha Kheiriddin

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

ECEC - Election Committee For Efficient Candidates

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

The Diplo Goat

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

Michael A. Cardozo

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

Clubbingabroad (Clubbing Abroad)

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

Woodard Function

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.

ungoogable

This request for creation has been declined. Please do not modify it.
This is an archived discussion. Please do not modify it.