Integrate Small Numbers: General Theory & Results

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Discussion Overview

The discussion revolves around the integration of small numbers and the related concept of infinite products, particularly in the context of quantum physics. Participants explore whether there exists a general theory or significant results regarding the multiplication of numbers close to one, as well as the implications of such products in various mathematical and physical frameworks.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • One participant suggests that integration involves summing small numbers, while multiplication of numbers close to one raises questions about general theories or results.
  • Another participant distinguishes between infinite sums (series) and infinite products, indicating a foundational difference in these concepts.
  • A different viewpoint expresses skepticism about the existence of extensive work on the topic, noting that logarithmic transformations can simplify products to sums, thus reverting to standard integrals.
  • One participant introduces a specific example from quantum physics involving non-commuting operators, highlighting the complexity of products in this context and suggesting that explicit problems may yield insights, though general results remain elusive.
  • There is mention of infinite products, but one participant clarifies that this is not precisely what they were seeking, although they found related resources interesting.

Areas of Agreement / Disagreement

Participants express differing views on the existence and significance of a general theory for products of small numbers, with some skepticism about the depth of existing research. The discussion remains unresolved regarding the applicability and implications of these concepts.

Contextual Notes

Some assumptions about the nature of products and their mathematical treatment are not fully explored, and the discussion does not resolve the complexities introduced by non-commuting factors in quantum mechanics.

jostpuur
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Rough idea behind integration is to sum lot's of small numbers (close to zero). Some problems lead to situations where you have to multiply lot's of numbers close to one. Is there any general theory of such products? Important results or tools?
 
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The first is called a series or an infinite sum. The second is called an infinite product.
 
I doubt that you can find a great body of work on the subject since taking a logarithm reduces to the sum and thus a standard integral.
 
In fact the main motivation for this product question comes from quantum physics,
[tex]\prod_{k=0}^n \exp(iH_k \Delta t /\hbar)[/tex], where product cannot be turned into sum in the exponent always since [tex]H_k[/tex] do not always commute.

So more generally, the product could be a product of matrices. Of course, if there is some explicit problem, you can see how things go and try to do something tricky, but I just asked this in a hope that there could to be some general results.

The infinite products only weren't precisly what I was after, but the Wolfram site did look interesting anyway.
 

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