Difference between revisions of "Jacobi theta 2"
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$$\vartheta_2(z,q)=2q^{\frac{1}{4}}\displaystyle\sum_{k=0}^{\infty} q^{k(k+1)} \cos(2k+1)z,$$ | $$\vartheta_2(z,q)=2q^{\frac{1}{4}}\displaystyle\sum_{k=0}^{\infty} q^{k(k+1)} \cos(2k+1)z,$$ | ||
where $\cos$ denotes the [[cosine]] function. | where $\cos$ denotes the [[cosine]] function. | ||
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| + | <div align="center"> | ||
| + | <gallery> | ||
| + | File:Jacobitheta2,q=0.5plot.png|Graph of $\vartheta_2(z,\frac{1}{2})$. | ||
| + | File:Complexjacobitheta2,q=0.5plot.png|Domain coloring of $\vartheta_2 \left(z,\frac{1}{2} \right)$. | ||
| + | </gallery> | ||
| + | </div> | ||
=Properties= | =Properties= | ||
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[[Sum of fourth powers of Jacobi theta 2 and Jacobi theta 4 equals fourth power of Jacobi theta 3]]<br /> | [[Sum of fourth powers of Jacobi theta 2 and Jacobi theta 4 equals fourth power of Jacobi theta 3]]<br /> | ||
[[Derivative of Jacobi theta 1 at 0]]<br /> | [[Derivative of Jacobi theta 1 at 0]]<br /> | ||
| + | [[Logarithm of quotient of Jacobi theta 2 equals the log of a quotient of cosines + a sum of sines]]<br /> | ||
| − | = | + | =References= |
| − | + | * {{BookReference|Special Functions|1960|Earl David Rainville|prev=Jacobi theta 1|next=Jacobi theta 3}}: $164. (2)$ | |
| − | + | * {{BookReference|Handbook of mathematical functions|1964|Milton Abramowitz|author2=Irene A. Stegun|prev=Jacobi theta 1|next=Jacobi theta 3}}: $16.27.2$ | |
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| − | + | {{:Jacobi theta footer}} | |
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[[Category:SpecialFunction]] | [[Category:SpecialFunction]] | ||
Latest revision as of 20:23, 25 June 2017
Let $q \in \mathbb{C}$ with $|q|<1$. The Jacobi $\vartheta_2$ function is defined by $$\vartheta_2(z,q)=2q^{\frac{1}{4}}\displaystyle\sum_{k=0}^{\infty} q^{k(k+1)} \cos(2k+1)z,$$ where $\cos$ denotes the cosine function.
Graph of $\vartheta_2(z,\frac{1}{2})$.
Domain coloring of $\vartheta_2 \left(z,\frac{1}{2} \right)$.
Properties
Squares of theta relation for Jacobi theta 1 and Jacobi theta 4
Squares of theta relation for Jacobi theta 2 and Jacobi theta 4
Squares of theta relation for Jacobi theta 3 and Jacobi theta 4
Squares of theta relation for Jacobi theta 4 and Jacobi theta 4
Sum of fourth powers of Jacobi theta 2 and Jacobi theta 4 equals fourth power of Jacobi theta 3
Derivative of Jacobi theta 1 at 0
Logarithm of quotient of Jacobi theta 2 equals the log of a quotient of cosines + a sum of sines
References
- 1960: Earl David Rainville: Special Functions ... (previous) ... (next): $164. (2)$
- 1964: Milton Abramowitz and Irene A. Stegun: Handbook of mathematical functions ... (previous) ... (next): $16.27.2$
