Beeman's algorithm

The graph of the function in gray is $e^{-\pi z^2}$, the Gaussian restricted to the real axis. The Gaussian does not have exponential type, but the functions in red and blue are one sided approximations that have exponential type $2\pi$.

In complex analysis, a branch of mathematics, a holomorphic function is said to be of exponential type C if its growth is bounded by the exponential function e^C|z| for some constant C as |z|→∞. When a function is bounded in this way, it is then possible to express it as certain kinds of convergent summations over a series of other complex functions, as well as understanding when it is possible to apply techniques such as Borel summation, or, for example, to apply the Mellin transform, or to perform approximations using the Euler-MacLaurin formula. The general case is handled by Nachbin's theorem, which defines the analogous notion of Ψ-type for a general function Ψ(z) as opposed to e^z.

Basic idea

A function f(z) defined on the complex plane is said to be of exponential type if there exist constants M and τ such that

$|f(r{e}^{i\theta })|\le M{e}^{\tau r}$

in the limit of $r\to \mathrm{\infty }$. Here, the complex variable z was written as $z=r{e}^{i\theta }$ to emphasize that the limit must hold in all directions θ. Letting τ stand for the infimum of all such τ, one then says that the function f is of exponential type τ.

For example, let $f(z)=\sin (\pi z)$. Then one says that $\sin (\pi z)$ is of exponential type π, since π is the smallest number that bounds the growth of $\sin (\pi z)$ along the imaginary axis. So, for this example, Carlson's theorem cannot apply, as it requires functions of exponential type less than π. Similarly, the Euler-MacLaurin formula cannot be applied either, as it, too, expresses an theorem ultimately anchored in the theory of finite differences.

Formal definition

A holomorphic function function $F(z)$ is said to be of exponential type $\sigma >0$ if for every $\epsilon >0$ there exists a constant $A_{\epsilon }$ such that

$|F(z)|\le A_{\epsilon }{e}^{(\sigma +\epsilon )\left|z\right|}$

for $\left|z\right|\to \mathrm{\infty }$ where $z\in \mathbb{ℂ}$. We say $F(z)$ is of exponential type if $F(z)$ is of exponential type $\sigma$ for some $\sigma >0$. The number

$\tau (F)=\sigma ={\mathrm{lim\; sup}}_{\left|z\right|\to \mathrm{\infty }}|z{|}^{-1}\log |F(z)|$

is the exponential type of $F(z)$.

Exponential type with respect to a symmetric convex body

Template:Harvtxt has given a generalization of exponential type for entire functions of several complex variables. Suppose $K$ is a convex, compact, and symmetric subset of ${\mathbb{ℝ}}^n$. It is known that for every such $K$ there is an associated norm $\Vert \cdot {\Vert }_K$ with the property that

$K=\{x\in {\mathbb{ℝ}}^n:\Vert x{\Vert }_K\le 1\}$.

In other words, $K$ is the unit ball in ${\mathbb{ℝ}}^n$ with respect to $\Vert \cdot {\Vert }_K$. The set

$K^{*}=\{y\in {\mathbb{ℝ}}^n:x\cdot y\le 1\text{ for all }x\in K\}$

is called the polar set and is also a convex, compact, and symmetric subset of ${\mathbb{ℝ}}^n$. Furthermore, we can write

$\Vert x{\Vert }_K={\sup }_{y\in K^{*}}|x\cdot y|$.

We extend $\Vert \cdot {\Vert }_K$ from ${\mathbb{ℝ}}^n$ to ${\mathbb{ℂ}}^n$ by

$\Vert z{\Vert }_K={\sup }_{y\in K^{*}}|z\cdot y|.$

An entire function $F(z)$ of $n$-complex variables is said to be of exponential type with respect to $K$ if for every $\epsilon >0$ there exists a constant $A_{\epsilon }$ such that

$|F(z)|<A_{\epsilon }{e}^{2\pi (1+\epsilon )\Vert z{\Vert }_K}$

for all $z\in {\mathbb{ℂ}}^n$.

Fréchet space

Collections of functions of exponential type $\tau$ can form a complete uniform space, namely a Fréchet space, by the topology induced by the countable family of norms

$\Vert f{\Vert }_n={\sup }_{z\in \mathbb{ℂ}}\exp [-(\tau +\frac{1}{n})|z\left|\right]|f(z)|$

See also

• Paley–Wiener theorem
• Paley–Wiener space

References

43 year old Petroleum Engineer Harry from Deep River, usually spends time with hobbies and interests like renting movies, property developers in singapore new condominium and vehicle racing. Constantly enjoys going to destinations like Camino Real de Tierra Adentro.

• Many property agents need to declare for the PIC grant in Singapore. However, not all of them know find out how to do the correct process for getting this PIC scheme from the IRAS. There are a number of steps that you need to do before your software can be approved.
  
  Naturally, you will have to pay a safety deposit and that is usually one month rent for annually of the settlement. That is the place your good religion deposit will likely be taken into account and will kind part or all of your security deposit. Anticipate to have a proportionate amount deducted out of your deposit if something is discovered to be damaged if you move out. It's best to you'll want to test the inventory drawn up by the owner, which can detail all objects in the property and their condition. If you happen to fail to notice any harm not already mentioned within the inventory before transferring in, you danger having to pay for it yourself.
  
  In case you are in search of an actual estate or Singapore property agent on-line, you simply should belief your intuition. It's because you do not know which agent is nice and which agent will not be. Carry out research on several brokers by looking out the internet. As soon as if you end up positive that a selected agent is dependable and reliable, you can choose to utilize his partnerise in finding you a home in Singapore. Most of the time, a property agent is taken into account to be good if he or she locations the contact data on his website. This may mean that the agent does not mind you calling them and asking them any questions relating to new properties in singapore in Singapore. After chatting with them you too can see them in their office after taking an appointment.
  
  Have handed an trade examination i.e Widespread Examination for House Brokers (CEHA) or Actual Property Agency (REA) examination, or equal; Exclusive brokers are extra keen to share listing information thus making certain the widest doable coverage inside the real estate community via Multiple Listings and Networking. Accepting a severe provide is simpler since your agent is totally conscious of all advertising activity related with your property. This reduces your having to check with a number of agents for some other offers. Price control is easily achieved. Paint work in good restore-discuss with your Property Marketing consultant if main works are still to be done. Softening in residential property prices proceed, led by 2.8 per cent decline within the index for Remainder of Central Region
  
  Once you place down the one per cent choice price to carry down a non-public property, it's important to accept its situation as it is whenever you move in – faulty air-con, choked rest room and all. Get round this by asking your agent to incorporate a ultimate inspection clause within the possibility-to-buy letter. HDB flat patrons routinely take pleasure in this security net. "There's a ultimate inspection of the property two days before the completion of all HDB transactions. If the air-con is defective, you can request the seller to repair it," says Kelvin.
  
  15.6.1 As the agent is an intermediary, generally, as soon as the principal and third party are introduced right into a contractual relationship, the agent drops out of the image, subject to any problems with remuneration or indemnification that he could have against the principal, and extra exceptionally, against the third occasion. Generally, agents are entitled to be indemnified for all liabilities reasonably incurred within the execution of the brokers´ authority.
  
  To achieve the very best outcomes, you must be always updated on market situations, including past transaction information and reliable projections. You could review and examine comparable homes that are currently available in the market, especially these which have been sold or not bought up to now six months. You'll be able to see a pattern of such report by clicking here It's essential to defend yourself in opposition to unscrupulous patrons. They are often very skilled in using highly unethical and manipulative techniques to try and lure you into a lure. That you must also protect your self, your loved ones, and personal belongings as you'll be serving many strangers in your home. Sign a listing itemizing of all of the objects provided by the proprietor, together with their situation. HSR Prime Recruiter 2010