Physics:Quantum calculus - Revision history

WikiHarold: Remove imported red links from Quantum page

2026-05-23T23:46:49Z

Remove imported red links from Quantum page

← Older revision		Revision as of 23:46, 23 May 2026
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	===q-integral===		===q-integral===
	A function ''F''(''x'') is a q-antiderivative of ''f''(''x'') if ''D''<sub>q</sub>''F''(''x'') = ''f''(''x''). The q-antiderivative (or q-integral) is denoted by <math display="inline">\int f(x) \, d_qx</math> and an expression for ''F''(''x'') can be found from the formula		A function ''F''(''x'') is a q-antiderivative of ''f''(''x'') if ''D''<sub>q</sub>''F''(''x'') = ''f''(''x''). The q-antiderivative (or q-integral) is denoted by <math display="inline">\int f(x) \, d_qx</math> and an expression for ''F''(''x'') can be found from the formula
	<math display="inline">\int f(x) \, d_qx = (1-q) \sum_{j=0}^\infty xq^j f(xq^j)</math> which is called the Jackson integral of ''f''(''x''). For {{nowrap\|0 < ''q'' < 1}}, the series converges to a function ''F''(''x'') on an interval (0,''A''] if \|''f''(''x'')''x''<sup>''α''</sup>\| is bounded on the interval ~~{{open-closed\|0, ''A''}}~~ for some {{nowrap\|0 ≤ ''α'' < 1}}.		<math display="inline">\int f(x) \, d_qx = (1-q) \sum_{j=0}^\infty xq^j f(xq^j)</math> which is called the Jackson integral of ''f''(''x''). For {{nowrap\|0 < ''q'' < 1}}, the series converges to a function ''F''(''x'') on an interval (0,''A''] if \|''f''(''x'')''x''<sup>''α''</sup>\| is bounded on the interval for some {{nowrap\|0 ≤ ''α'' < 1}}.

	The q-integral is a Riemann–Stieltjes integral with respect to a step function having infinitely many points of increase at the points ''q''<sup>''j''</sup>, with the jump at the point ''q''<sup>''j''</sup> being ''q''<sup>''j''</sup>. If we call this step function ''g''<sub>''q''</sub>(''t'') then ''dg''<sub>''q''</sub>(''t'') = ''d''<sub>''q''</sub>''t''.<ref>{{cite journal\|url=http://www.mat.uc.pt/preprints/ps/p0432.pdf\|doi=10.1090/S0002-9939-06-08285-2\|jstor=4098119\|year=2006\|last1=Abreu\|first1=Luis Daniel\|title=Functions q-Orthogonal with Respect to Their Own Zeros\|journal=Proceedings of the American Mathematical Society\|volume=134\|issue=9\|pages=2695–2702\|doi-access=free}}</ref>		The q-integral is a Riemann–Stieltjes integral with respect to a step function having infinitely many points of increase at the points ''q''<sup>''j''</sup>, with the jump at the point ''q''<sup>''j''</sup> being ''q''<sup>''j''</sup>. If we call this step function ''g''<sub>''q''</sub>(''t'') then ''dg''<sub>''q''</sub>(''t'') = ''d''<sub>''q''</sub>''t''.<ref>{{cite journal\|url=http://www.mat.uc.pt/preprints/ps/p0432.pdf\|doi=10.1090/S0002-9939-06-08285-2\|jstor=4098119\|year=2006\|last1=Abreu\|first1=Luis Daniel\|title=Functions q-Orthogonal with Respect to Their Own Zeros\|journal=Proceedings of the American Mathematical Society\|volume=134\|issue=9\|pages=2695–2702\|doi-access=free}}</ref>

	===h-integral===		===h-integral===
	A function ''F''(''x'') is an h-antiderivative of ''f''(''x'') if ''D''<sub>''h''</sub>''F''(''x'') = ''f''(''x''). The h-integral is denoted by <math display="inline">\int f(x) \, d_hx</math>. If ''a'' and ''b'' differ by an integer multiple of ''h'' then the definite integral <math display="inline">\int_a^b f(x) \, d_hx</math> is given by a Riemann sum of ''f''(''x'') on the interval ~~{{closed-closed\|''a'', ''b''}}~~ partitioned into subintervals of equal width ''h''. The motivation of h-integral is also comes from the riemann sum of f(x), follow the idea of the motivation of classical integral we get that some of the properties of classical integral also holds in h-integral. But the differences is we avoid to taking the limit. This notion have abroad application in Numerical Analysis especially in Finite difference calculus		A function ''F''(''x'') is an h-antiderivative of ''f''(''x'') if ''D''<sub>''h''</sub>''F''(''x'') = ''f''(''x''). The h-integral is denoted by <math display="inline">\int f(x) \, d_hx</math>. If ''a'' and ''b'' differ by an integer multiple of ''h'' then the definite integral <math display="inline">\int_a^b f(x) \, d_hx</math> is given by a Riemann sum of ''f''(''x'') on the interval partitioned into subintervals of equal width ''h''. The motivation of h-integral is also comes from the riemann sum of f(x), follow the idea of the motivation of classical integral we get that some of the properties of classical integral also holds in h-integral. But the differences is we avoid to taking the limit. This notion have abroad application in Numerical Analysis especially in Finite difference calculus

	== Example ==		== Example ==
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	* {{cite book \|last=Exton \|first=H. \|year=1983 \|title=q-Hypergeometric Functions and Applications \|location=New York \|publisher=Halstead Press \|isbn=0-85312-491-4 }}		* {{cite book \|last=Exton \|first=H. \|year=1983 \|title=q-Hypergeometric Functions and Applications \|location=New York \|publisher=Halstead Press \|isbn=0-85312-491-4 }}
	* {{cite book \|first1=Victor \|last1=Kac \|first2=Pokman \|last2=Cheung \|title=Quantum calculus \|series=Universitext \|publisher=Springer-Verlag \|year=2002 \|isbn=0-387-95341-8 }}		* {{cite book \|first1=Victor \|last1=Kac \|first2=Pokman \|last2=Cheung \|title=Quantum calculus \|series=Universitext \|publisher=Springer-Verlag \|year=2002 \|isbn=0-387-95341-8 }}
	~~[[Category:Quantum mechanics\| ]]~~
	~~[[Category:Differential calculus\|*]]~~

	{{Sourceattribution\|Quantum calculus}}		{{Sourceattribution\|Quantum calculus}}

WikiHarold: Clean Quantum page image and red links

2026-05-23T23:33:41Z

Clean Quantum page image and red links

← Older revision		Revision as of 23:33, 23 May 2026
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	<div style="flex:1; line-height:1.45; color:#006b45; column-count:2; column-gap:32px; column-rule:1px solid #b8d8c8;">		<div style="flex:1; line-height:1.45; color:#006b45; column-count:2; column-gap:32px; column-rule:1px solid #b8d8c8;">
	'''Quantum calculus''', sometimes called '''calculus without limits''', is equivalent to traditional infinitesimal calculus without the notion of ~~[[Limit of a function\|~~limits]]. Unlike traditional calculus, which applying the concept of limits to analyze function. in fact the property of traditional calculus it is also holds in Quantum Calculus. In Quantum Calculus there are two distinct type of calculus i.e It defines "q-calculus" and "h-calculus", where h ostensibly stands for Planck's constant while ''q'' stands for quantum. The two parameters are related by the formula		'''Quantum calculus''', sometimes called '''calculus without limits''', is equivalent to traditional infinitesimal calculus without the notion of limits. Unlike traditional calculus, which applying the concept of limits to analyze function. in fact the property of traditional calculus it is also holds in Quantum Calculus. In Quantum Calculus there are two distinct type of calculus i.e It defines "q-calculus" and "h-calculus", where h ostensibly stands for Planck's constant while ''q'' stands for quantum. The two parameters are related by the formula
	:<math>q = e^{i h} = e^{2 \pi i \hbar}</math>		:<math>q = e^{i h} = e^{2 \pi i \hbar}</math>

	where <math display="inline"> \hbar = \frac{h}{2 \pi}</math> is the ~~[[Physics:Reduced Planck constant\|~~reduced Planck constant]].		where <math display="inline"> \hbar = \frac{h}{2 \pi}</math> is the reduced Planck constant.
	</div>		</div>

	<div style="width:300px;">		<div style="width:300px;">
	[[File:~~File not found~~.~~png~~\|thumb\|280px\|~~No image available~~.]]		[[File:Quantum_calculus_concept_map.svg\|thumb\|280px\|calculus in the Quantum Collection.]]
	</div>		</div>

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	==Differentiation==		==Differentiation==

	In the q-calculus and h-calculus, ~~[[Differential of a function\|~~differentials]] of functions are defined as		In the q-calculus and h-calculus, differentials of functions are defined as

	:<math>d_q(f(x)) = f(qx) - f(x)</math>		:<math>d_q(f(x)) = f(qx) - f(x)</math>
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	:<math>d_h(f(x)) = f(x + h) - f(x)</math>		:<math>d_h(f(x)) = f(x + h) - f(x)</math>

	respectively. ~~[[Derivative]]s~~ of functions are then defined as fractions by the ~~[[Q-derivative\|~~q-derivative]]		respectively. Derivatives of functions are then defined as fractions by the q-derivative

	:<math>D_q(f(x)) = \frac{d_q(f(x))}{d_q(x)} = \frac{f(qx) - f(x)}{(q - 1)x}</math>		:<math>D_q(f(x)) = \frac{d_q(f(x))}{d_q(x)} = \frac{f(qx) - f(x)}{(q - 1)x}</math>
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	:<math>D_h(f(x)) = \frac{d_h(f(x))}{d_h(x)} = \frac{f(x + h) - f(x)}{h}</math>		:<math>D_h(f(x)) = \frac{d_h(f(x))}{d_h(x)} = \frac{f(x + h) - f(x)}{h}</math>

	In the ~~[[Limit of a function\|~~limit]], as h goes to 0, or equivalently as q goes to 1, these expressions take on the form of the derivative of classical calculus.		In the limit, as h goes to 0, or equivalently as q goes to 1, these expressions take on the form of the derivative of classical calculus.

	==Integration==		==Integration==
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	===q-integral===		===q-integral===
	A function ''F''(''x'') is a q-antiderivative of ''f''(''x'') if ''D''<sub>q</sub>''F''(''x'') = ''f''(''x''). The q-antiderivative (or q-integral) is denoted by <math display="inline">\int f(x) \, d_qx</math> and an expression for ''F''(''x'') can be found from the formula		A function ''F''(''x'') is a q-antiderivative of ''f''(''x'') if ''D''<sub>q</sub>''F''(''x'') = ''f''(''x''). The q-antiderivative (or q-integral) is denoted by <math display="inline">\int f(x) \, d_qx</math> and an expression for ''F''(''x'') can be found from the formula
	<math display="inline">\int f(x) \, d_qx = (1-q) \sum_{j=0}^\infty xq^j f(xq^j)</math> which is called the [[Jackson integral]] of ''f''(''x''). For {{nowrap\|0 < ''q'' < 1}}, the series converges to a function ''F''(''x'') on an interval (0,''A''] if \|''f''(''x'')''x''<sup>''α''</sup>\| is bounded on the interval {{open-closed\|0, ''A''}} for some {{nowrap\|0 ≤ ''α'' < 1}}.		<math display="inline">\int f(x) \, d_qx = (1-q) \sum_{j=0}^\infty xq^j f(xq^j)</math> which is called the Jackson integral of ''f''(''x''). For {{nowrap\|0 < ''q'' < 1}}, the series converges to a function ''F''(''x'') on an interval (0,''A''] if \|''f''(''x'')''x''<sup>''α''</sup>\| is bounded on the interval {{open-closed\|0, ''A''}} for some {{nowrap\|0 ≤ ''α'' < 1}}.

	The q-integral is a [[Riemann–Stieltjes integral]] with respect to a ~~[[Step function\|~~step function]] having infinitely many points of increase at the points ''q''<sup>''j''</sup>, with the jump at the point ''q''<sup>''j''</sup> being ''q''<sup>''j''</sup>. If we call this step function ''g''<sub>''q''</sub>(''t'') then ''dg''<sub>''q''</sub>(''t'') = ''d''<sub>''q''</sub>''t''.<ref>{{cite journal\|url=http://www.mat.uc.pt/preprints/ps/p0432.pdf\|doi=10.1090/S0002-9939-06-08285-2\|jstor=4098119\|year=2006\|last1=Abreu\|first1=Luis Daniel\|title=Functions q-Orthogonal with Respect to Their Own Zeros\|journal=Proceedings of the American Mathematical Society\|volume=134\|issue=9\|pages=2695–2702\|doi-access=free}}</ref>		The q-integral is a Riemann–Stieltjes integral with respect to a step function having infinitely many points of increase at the points ''q''<sup>''j''</sup>, with the jump at the point ''q''<sup>''j''</sup> being ''q''<sup>''j''</sup>. If we call this step function ''g''<sub>''q''</sub>(''t'') then ''dg''<sub>''q''</sub>(''t'') = ''d''<sub>''q''</sub>''t''.<ref>{{cite journal\|url=http://www.mat.uc.pt/preprints/ps/p0432.pdf\|doi=10.1090/S0002-9939-06-08285-2\|jstor=4098119\|year=2006\|last1=Abreu\|first1=Luis Daniel\|title=Functions q-Orthogonal with Respect to Their Own Zeros\|journal=Proceedings of the American Mathematical Society\|volume=134\|issue=9\|pages=2695–2702\|doi-access=free}}</ref>

	===h-integral===		===h-integral===
	A function ''F''(''x'') is an h-antiderivative of ''f''(''x'') if ''D''<sub>''h''</sub>''F''(''x'') = ''f''(''x''). The h-integral is denoted by <math display="inline">\int f(x) \, d_hx</math>. If ''a'' and ''b'' differ by an integer multiple of ''h'' then the definite integral <math display="inline">\int_a^b f(x) \, d_hx</math> is given by a [[Riemann sum]] of ''f''(''x'') on the interval {{closed-closed\|''a'', ''b''}} partitioned into subintervals of equal width ''h''. The motivation of h-integral is also comes from the riemann sum of f(x), follow the idea of the motivation of classical integral we get that some of the properties of classical integral also holds in h-integral. But the differences is we avoid to taking the limit. This notion have abroad application in Numerical Analysis especially in Finite difference calculus		A function ''F''(''x'') is an h-antiderivative of ''f''(''x'') if ''D''<sub>''h''</sub>''F''(''x'') = ''f''(''x''). The h-integral is denoted by <math display="inline">\int f(x) \, d_hx</math>. If ''a'' and ''b'' differ by an integer multiple of ''h'' then the definite integral <math display="inline">\int_a^b f(x) \, d_hx</math> is given by a Riemann sum of ''f''(''x'') on the interval {{closed-closed\|''a'', ''b''}} partitioned into subintervals of equal width ''h''. The motivation of h-integral is also comes from the riemann sum of f(x), follow the idea of the motivation of classical integral we get that some of the properties of classical integral also holds in h-integral. But the differences is we avoid to taking the limit. This notion have abroad application in Numerical Analysis especially in Finite difference calculus

	== Example ==		== Example ==
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	respectively. The expression <math>[n]_q x^{n - 1}</math> is then the q-calculus analogue of the simple power rule for		respectively. The expression <math>[n]_q x^{n - 1}</math> is then the q-calculus analogue of the simple power rule for
	positive integral powers. In this sense, the function <math>x^n</math> is still ''nice'' in the q-calculus, but rather ugly in the h-calculus – the h-calculus analog of <math>x^n</math> is instead the falling factorial, <math>(x)_n := x (x-1) \cdots (x-n+1).</math>		positive integral powers. In this sense, the function <math>x^n</math> is still ''nice'' in the q-calculus, but rather ugly in the h-calculus – the h-calculus analog of <math>x^n</math> is instead the falling factorial, <math>(x)_n := x (x-1) \cdots (x-n+1).</math>
	One may proceed further and develop, for example, equivalent notions of ~~[[Q-derivative\|~~Taylor expansion]], et cetera, and even arrive at q-calculus analogues for all of the usual functions one would want to have, such as an analogue for the ~~[[Sine\|~~sine]] function whose q-derivative is the appropriate analogue for the ~~[[Cosine\|~~cosine]].		One may proceed further and develop, for example, equivalent notions of Taylor expansion, et cetera, and even arrive at q-calculus analogues for all of the usual functions one would want to have, such as an analogue for the sine function whose q-derivative is the appropriate analogue for the cosine.

	== History ==		== History ==
	The h-calculus is just the calculus of finite differences, which had been studied by [[Biography:George Boole\|George Boole]] and others, and has proven useful in a number of fields, among them ~~[[Combinatorics\|~~combinatorics]] and ~~[[Physics:Fluid mechanics\|~~fluid mechanics]]. The q-calculus, while dating in a sense back to [[Biography:Leonhard Euler\|Leonhard Euler]] and Carl Gustav Jacobi, is only recently beginning to see more usefulness in [[Physics:Quantum mechanics\|quantum mechanics]], having an intimate connection with commutativity relations and [[Lie algebra]].		The h-calculus is just the calculus of finite differences, which had been studied by [[Biography:George Boole\|George Boole]] and others, and has proven useful in a number of fields, among them combinatorics and fluid mechanics. The q-calculus, while dating in a sense back to [[Biography:Leonhard Euler\|Leonhard Euler]] and Carl Gustav Jacobi, is only recently beginning to see more usefulness in [[Physics:Quantum mechanics\|quantum mechanics]], having an intimate connection with commutativity relations and Lie algebra.

	== See also ==		== See also ==
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	* {{cite book \|last=Exton \|first=H. \|year=1983 \|title=q-Hypergeometric Functions and Applications \|location=New York \|publisher=Halstead Press \|isbn=0-85312-491-4 }}		* {{cite book \|last=Exton \|first=H. \|year=1983 \|title=q-Hypergeometric Functions and Applications \|location=New York \|publisher=Halstead Press \|isbn=0-85312-491-4 }}
	* {{cite book \|first1=Victor \|last1=Kac \|first2=Pokman \|last2=Cheung \|title=Quantum calculus \|series=Universitext \|publisher=Springer-Verlag \|year=2002 \|isbn=0-387-95341-8 }}		* {{cite book \|first1=Victor \|last1=Kac \|first2=Pokman \|last2=Cheung \|title=Quantum calculus \|series=Universitext \|publisher=Springer-Verlag \|year=2002 \|isbn=0-387-95341-8 }}

	~~{{Quantum mechanics topics\|state=expanded}}~~
	[[Category:Quantum mechanics\| ]]		[[Category:Quantum mechanics\| ]]
	[[Category:Differential calculus\|*]]		[[Category:Differential calculus\|*]]

	{{Sourceattribution\|Quantum calculus}}		{{Sourceattribution\|Quantum calculus}}

WikiHarold: Use Quantum See also index module

2026-05-23T22:20:54Z

Use Quantum See also index module

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	== See also ==		== See also ==
	* [[Noncommutative geometry]]		{{#invoke:PhysicsQC\|tocHeadingAndList\|Physics:Quantum basics/See also}}
	* [[Quantum differential calculus]]
	* Time scale calculus
	* [[Q-analog\|~~q-analog]]~~
	* [[Basic hypergeometric series]]
	* [[Quantum ~~dilogarithm]]~~

	== Further reading ==		== Further reading ==

Harold: Add missing image fallback to Quantum header

2026-05-17T22:32:53Z

Add missing image fallback to Quantum header

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	<div style="width:300px;">		<div style="width:300px;">
	~~<!--~~ No ~~lead~~ image available ~~in existing page~~. ~~-->~~		[[File:File not found.png\|thumb\|280px\|No image available.]]
	</div>		</div>

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Restore Quantum article header template

@@ Line 1: / Line 1: @@
 '''Quantum calculus''', sometimes called '''calculus without limits''', is equivalent to traditional infinitesimal calculus without the notion of [[Limit of a function|limits]]. Unlike traditional calculus, which applying the concept of limits to analyze function. in fact the property of traditional calculus it is also holds in Quantum Calculus. In Quantum Calculus there are two distinct type of calculus i.e It defines "q-calculus" and "h-calculus", where h ostensibly stands for Planck's constant while ''q'' stands for quantum. The two parameters are related by the formula
 :<math>q = e^{i h} = e^{2 \pi i \hbar}</math>
 where <math display="inline"> \hbar = \frac{h}{2 \pi}</math> is the [[Physics:Reduced Planck constant|reduced Planck constant]].
 ==Differentiation==

imported>WikiHarold: change

2024-02-05T10:44:14Z

change

← Older revision	Revision as of 10:44, 5 February 2024
(No difference)

imported>WikiHarold: change

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change

New page

'''Quantum calculus''', sometimes called '''calculus without limits''', is equivalent to traditional infinitesimal calculus without the notion of [[Limit of a function|limits]]. Unlike traditional calculus, which applying the concept of limits to analyze function. in fact the property of traditional calculus it is also holds in Quantum Calculus. In Quantum Calculus there are two distinct type of calculus i.e It defines "q-calculus" and "h-calculus", where h ostensibly stands for Planck's constant while ''q'' stands for quantum. The two parameters are related by the formula
:<math>q = e^{i h} = e^{2 \pi i \hbar}</math>

where <math display="inline"> \hbar = \frac{h}{2 \pi}</math> is the [[Physics:Reduced Planck constant|reduced Planck constant]].

==Differentiation==

In the q-calculus and h-calculus, [[Differential of a function|differentials]] of functions are defined as

:<math>d_q(f(x)) = f(qx) - f(x)</math>

and

:<math>d_h(f(x)) = f(x + h) - f(x)</math>

respectively. [[Derivative]]s of functions are then defined as fractions by the [[Q-derivative|q-derivative]]

:<math>D_q(f(x)) = \frac{d_q(f(x))}{d_q(x)} = \frac{f(qx) - f(x)}{(q - 1)x}</math>

and by

:<math>D_h(f(x)) = \frac{d_h(f(x))}{d_h(x)} = \frac{f(x + h) - f(x)}{h}</math>

In the [[Limit of a function|limit]], as h goes to 0, or equivalently as q goes to 1, these expressions take on the form of the derivative of classical calculus.

==Integration==

===q-integral===
A function ''F''(''x'') is a q-antiderivative of ''f''(''x'') if ''D''q''F''(''x'') = ''f''(''x''). The q-antiderivative (or q-integral) is denoted by <math display="inline">\int f(x) \, d_qx</math> and an expression for ''F''(''x'') can be found from the formula
<math display="inline">\int f(x) \, d_qx = (1-q) \sum_{j=0}^\infty xq^j f(xq^j)</math> which is called the [[Jackson integral]] of ''f''(''x''). For {{nowrap|0 < ''q'' < 1}}, the series converges to a function ''F''(''x'') on an interval (0,''A''] if |''f''(''x'')''x''''α''| is bounded on the interval {{open-closed|0, ''A''}} for some {{nowrap|0 ≤ ''α'' < 1}}.

The q-integral is a [[Riemann–Stieltjes integral]] with respect to a [[Step function|step function]] having infinitely many points of increase at the points ''q''''j'', with the jump at the point ''q''''j'' being ''q''''j''. If we call this step function ''g''''q''(''t'') then ''dg''''q''(''t'') = ''d''''q''''t''.<ref>{{cite journal|url=http://www.mat.uc.pt/preprints/ps/p0432.pdf|doi=10.1090/S0002-9939-06-08285-2|jstor=4098119|year=2006|last1=Abreu|first1=Luis Daniel|title=Functions q-Orthogonal with Respect to Their Own Zeros|journal=Proceedings of the American Mathematical Society|volume=134|issue=9|pages=2695–2702|doi-access=free}}</ref>

===h-integral===
A function ''F''(''x'') is an h-antiderivative of ''f''(''x'') if ''D''''h''''F''(''x'') = ''f''(''x''). The h-integral is denoted by <math display="inline">\int f(x) \, d_hx</math>. If ''a'' and ''b'' differ by an integer multiple of ''h'' then the definite integral <math display="inline">\int_a^b f(x) \, d_hx</math> is given by a [[Riemann sum]] of ''f''(''x'') on the interval {{closed-closed|''a'', ''b''}} partitioned into subintervals of equal width ''h''. The motivation of h-integral is also comes from the riemann sum of f(x), follow the idea of the motivation of classical integral we get that some of the properties of classical integral also holds in h-integral. But the differences is we avoid to taking the limit. This notion have abroad application in Numerical Analysis especially in Finite difference calculus

== Example ==
The derivative of the function <math>x^n</math> (for some positive integer <math>n</math>) in the classical calculus is <math>nx^{n-1}</math>. The corresponding expressions in q-calculus and h-calculus are

:<math>D_q(x^n) = \frac{q^n - 1}{q - 1} x^{n - 1} = [n]_q\ x^{n - 1}</math>

with the q-bracket

:<math>[n]_q = \frac{q^n - 1}{q - 1}</math>

and

:<math>D_h(x^n) = n x^{n - 1} + \frac{n(n-1)}{2} h x^{n - 2} + \cdots + h^{n - 1}</math>

respectively. The expression <math>[n]_q x^{n - 1}</math> is then the q-calculus analogue of the simple power rule for
positive integral powers. In this sense, the function <math>x^n</math> is still ''nice'' in the q-calculus, but rather ugly in the h-calculus – the h-calculus analog of <math>x^n</math> is instead the falling factorial, <math>(x)_n := x (x-1) \cdots (x-n+1).</math>
One may proceed further and develop, for example, equivalent notions of [[Q-derivative|Taylor expansion]], et cetera, and even arrive at q-calculus analogues for all of the usual functions one would want to have, such as an analogue for the [[Sine|sine]] function whose q-derivative is the appropriate analogue for the [[Cosine|cosine]].

== History ==
The h-calculus is just the calculus of finite differences, which had been studied by [[Biography:George Boole|George Boole]] and others, and has proven useful in a number of fields, among them [[Combinatorics|combinatorics]] and [[Physics:Fluid mechanics|fluid mechanics]]. The q-calculus, while dating in a sense back to [[Biography:Leonhard Euler|Leonhard Euler]] and Carl Gustav Jacobi, is only recently beginning to see more usefulness in [[Physics:Quantum mechanics|quantum mechanics]], having an intimate connection with commutativity relations and [[Lie algebra]].

== See also ==
* [[Noncommutative geometry]]
* [[Quantum differential calculus]]
* Time scale calculus
* [[Q-analog|q-analog]]
* [[Basic hypergeometric series]]
* [[Quantum dilogarithm]]

== Further reading ==

* George Gasper, Mizan Rahman, ''Basic Hypergeometric Series'', 2nd ed, Cambridge University Press (2004), {{ISBN|978-0-511-52625-1}}, {{doi|10.1017/CBO9780511526251}}

==References==
{{reflist}}

* {{cite journal |first=F. H. |last=Jackson |year=1908 |title=On ''q''-functions and a certain difference operator|journal= Transactions of the Royal Society of Edinburgh|volume=46 |issue= 2|pages=253–281 |doi=10.1017/S0080456800002751|s2cid=123927312 }}
* {{cite book |last=Exton |first=H. |year=1983 |title=q-Hypergeometric Functions and Applications |location=New York |publisher=Halstead Press |isbn=0-85312-491-4 }}
* {{cite book |first1=Victor |last1=Kac |first2=Pokman |last2=Cheung |title=Quantum calculus |series=Universitext |publisher=Springer-Verlag |year=2002 |isbn=0-387-95341-8 }}

{{Quantum mechanics topics|state=expanded}}
[[Category:Quantum mechanics| ]]
[[Category:Differential calculus|*]]

{{Sourceattribution|Quantum calculus}}