Complex Analysis: Defining Complex Volume & Sphere w/ Winding Number

In summary, the conversation discusses the idea of adding a third axis, a winding number axis, to the complex plane to create a "complex volume." This would allow for a way to distinguish between different winding numbers for points on a contour. However, it is noted that this concept is similar to Riemann surfaces and their use in making multiple valued functions single valued. The potential applications and implications of this concept are also briefly discussed.
  • #1
Jonny_trigonometry
452
0
Suppose you have a unit circle in the complex plane [tex] e^{it}, -\infty \leq t \leq \infty[/tex]. The contour will wind around forever, so at all points in the contour, there are an infinite amount of possible winding numbers, although they are all multiples of 2pi with a well defined contour boundry, such as if t started at zero, they are not well defined if t starts at negative infinity, so this is what makes me think that they (the winding numbers) don't have to "step" by multiples of 2pi at each point in the contour, rather they can take all values in between also.

I was wondering if maybe we could exend another dimention to the complex plane to make it "the complex volume" with a real axis, an imaginary axis, and a winding number axis. so now this is kind of like a new set of numbers, w= a + bi + cw, where all numbers can have an intrinsic winding number of their own regardless of wether or not it is part of a contour... I was trying to think of how a sphere could be defined in this way, and I haven't got that far... Is there any way this can be done?
 
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  • #2
You can certainly form the sets CxR or CxZ, but what you want to do with them is beyond me, since complex numbers do not have winding numbers.
 
  • #3
You could define a 3rd axis with a choice of real or complex number. It would be interesting how this works out in spherical or cylindrical coordinate systems.

I'm just guessing, maybe a surface integral of a closed surface would equal 0, (analogous to Cauchy's theorem) and you could do stuff with residues, that would be neat.
 
  • #4
You could define a 3rd axis with a choice of real or complex number. It would be interesting how this works out in spherical or cylindrical coordinate systems.

I'm just guessing, maybe a surface integral of a closed surface would equal 0, (analogous to Cauchy's theorem) and you could do stuff with residues, that would be neat.
 
  • #5
You could define a 3rd axis with a choice of real or complex number. It would be interesting how this works out in spherical or cylindrical coordinate systems.

I'm just guessing, maybe a surface integral of a closed surface would equal 0, (analogous to Cauchy's theorem) and you could do stuff with residues, that would be neat.
 
  • #6
oops sorry, had some connection problem.
 
  • #7
matt grime said:
You can certainly form the sets CxR or CxZ, but what you want to do with them is beyond me, since complex numbers do not have winding numbers.

ya, i don't think this would work... but I'm beckoned by the idea that (at least for a contour) the way to distinguish how many times it was wound around a point is by simply "layering" the contour as if it's going up a spiral staircase. The point a + bi with winding # 2.3 is not the same as the point a + bi with winding # 2PI + 2.3... you know?
 
  • #8
You can certianly consider CxC too and look at it with holomorphic stuff in mind but it still has nottihng to do with the intrinsic winding number of a point since that makes no sense.
 
  • #9
Jonny_trigonometry said:
ya, i don't think this would work... but I'm beckoned by the idea that (at least for a contour) the way to distinguish how many times it was wound around a point is by simply "layering" the contour as if it's going up a spiral staircase. The point a + bi with winding # 2.3 is not the same as the point a + bi with winding # 2PI + 2.3... you know?
in that case yo'u're verging towards riemann surfaces, which roughly speaking turn multiple valued tihngs like log or sqrt into single valued functions by gluing together copies of parts of C, but there is a different one for each function.
 
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  • #10
waht said:
You could define a 3rd axis with a choice of real or complex number. It would be interesting how this works out in spherical or cylindrical coordinate systems.
I'm just guessing, maybe a surface integral of a closed surface would equal 0, (analogous to Cauchy's theorem) and you could do stuff with residues, that would be neat.

ya i thought for a while about what it would be like to add a real axis perp to the complex plane, and that is basically like taking a bunch of complex planes and stacking them on top of each other. All cross products would stay within the plane of the two original vecotrs. The cauchy theorem could be used on arbitrary planes within this volume and stuff. It would be neat to explore all the implications, maybe it would be useful I don't know.
 
  • #11
matt grime said:
You can certianly consider CxC too and look at it with holomorphic stuff in mind but it still has nottihng to do with the intrinsic winding number of a point since that makes no sense.

ya it doesn't make any sense, because it's based on the contour that the point is part of. It's like trying to define another dimention for all trig functions to distinguish between periods. For the winding number of an intrinsic point, it is always a function w/respect to some other point... What if that other point was dynamically changing? What would happen if you were to continuously compute the winding number for each point on a contour based on a different contour, say, the derivative of the first contour?
 
  • #12
matt grime said:
in that case yo'u're verging towards riemann surfaces, which roughly speaking turn multiple valued tihngs like log or sqrt into single valued functions by gluing together copies of parts of C, but there is a different one for each function.


I'll check that stuff out... I just finnished complex analysis this semester, so I haven't really got into riemann surfaces and stuff yet, although they sound very cool.
 

1. What is complex analysis?

Complex analysis is a branch of mathematics that deals with the study of complex numbers and their functions. It involves the use of techniques from calculus and algebra to analyze and understand functions of a complex variable.

2. What is a complex volume?

A complex volume is a three-dimensional region in the complex plane that is enclosed by a closed curve. It can be thought of as the counterpart of a two-dimensional region in the real plane.

3. How is a complex volume defined?

A complex volume is defined as the set of all points in the complex plane that lie within a closed curve. This curve can be described by a parametric equation involving complex numbers.

4. What is a sphere with winding number in complex analysis?

In complex analysis, a sphere with winding number is a three-dimensional surface in the complex plane that is formed by rotating a closed curve around a fixed axis. The winding number is a measure of the number of times the curve wraps around the axis.

5. How is the winding number of a curve determined?

The winding number of a curve is determined by counting the number of times the curve winds around a fixed point in the complex plane in a counterclockwise direction. It can also be calculated using the Cauchy integral formula or the Cauchy-Goursat theorem.

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