A counter-example to the Gelfond–Schneider theorem

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Discussion Overview

The discussion revolves around the implications of the Gelfond–Schneider theorem, particularly in relation to the expression of negative bases raised to transcendental exponents. Participants explore the behavior of the expression (-1)^e and its potential outcomes, questioning whether it can yield defined values or remains undefined.

Discussion Character

  • Exploratory
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant presents a calculation involving (-1)^e, suggesting that it leads to multiple conjectures about its value, including possibilities of being 1, -1, i, -i, or undefined.
  • Another participant introduces a complex number representation of a^b when a < 0, indicating that the expression can be interpreted in terms of its magnitude and argument.
  • There is a discussion about the behavior of the function as b increases, with implications for the graph of the real and imaginary parts of the expression.
  • Questions arise regarding the specific outcomes when substituting values into the formula, particularly when a = -1 and b = 2, leading to further exploration of Euler's formula.

Areas of Agreement / Disagreement

Participants express differing views on the implications of the Gelfond–Schneider theorem and the behavior of the expression (-1)^e. There is no consensus on whether the expression yields defined values or remains undefined, and the discussion includes competing interpretations of the mathematical principles involved.

Contextual Notes

The discussion highlights the complexity of defining expressions involving negative bases and transcendental exponents, with unresolved assumptions about the nature of these calculations and their implications under the Gelfond–Schneider theorem.

n_kelthuzad
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Gelfond–Schneider theorem can be seen here(http://en.wikipedia.org/wiki/Gelfond's_theorem) wiki.
----------------------------------------------------------------------------------
Given a simple calculation:
a^b
where a<0;
and let b be a fraction : u/v
so there are 3 possible ways of u and v s' arrangement:
I. u even, v odd
II. u odd, v odd
III. u odd, v even.
in I, a^b>0
in II, a^b<0
in III, a^b is a complex number.​
then the part of my study kicks in:
So what happens when b is a transcedental number?
since b is transcedental;
it no longer can be described as a fraction.
so the above 3 rules doesn't apply.
So I pick one of the most common transcedental numbers for b : b = e
and (-1) for a.
so the equation is: (-1)^e
it is known that e=1+1/1!+1/2!=1/3!+...
so it becomes: (-1)^1*(-1)^1*(-1)^(1/2)*(-1)^(1/6)...
and for all exponents starting from the 3rd one: the above (III) rule applys.
so the answer to the equation is : -1*-1*i*i*i...
=i^∞
(so this is what I was working up to now)
so there can be 2 conjectures:
1. (-1)^e = 1 or -1 or i or -i
2. the equation is undefined.
but either way, we will just leave it alone for a moment.
------------------------------------------------------------------------
If the Gelfond–Schneider theorem is true:
then (-e)^e must be transcendental.
and (-e)^e is equal to [(-1)^e]*[e^e]
still if the theorem is true; e^e must be transcendental.
then assume 1 from the above conjecture is true:
there are 2 complex answers of (-e)^e
or assume 2 is true:
(-e)^e is undefined
so clearly either way, it is a paradox.


By Victor Lu, 16
Burnside High School, Christchurch, NZ
496200691@qq.com
 
Mathematics news on Phys.org
n_kelthuzad said:
Gelfond–Schneider theorem can be seen here(http://en.wikipedia.org/wiki/Gelfond's_theorem) wiki.
----------------------------------------------------------------------------------
Given a simple calculation:
a^b
where a<0;
and let b be a fraction : u/v
so there are 3 possible ways of u and v s' arrangement:
I. u even, v odd
II. u odd, v odd
III. u odd, v even.
in I, a^b>0
in II, a^b<0
in III, a^b is a complex number.​
then the part of my study kicks in:
So what happens when b is a transcedental number?
since b is transcedental;
it no longer can be described as a fraction.
so the above 3 rules doesn't apply.
So I pick one of the most common transcedental numbers for b : b = e
and (-1) for a.
so the equation is: (-1)^e
it is known that e=1+1/1!+1/2!=1/3!+...
so it becomes: (-1)^1*(-1)^1*(-1)^(1/2)*(-1)^(1/6)...
and for all exponents starting from the 3rd one: the above (III) rule applys.
so the answer to the equation is : -1*-1*i*i*i...
=i^∞
(so this is what I was working up to now)
so there can be 2 conjectures:
1. (-1)^e = 1 or -1 or i or -i
2. the equation is undefined.
but either way, we will just leave it alone for a moment.
------------------------------------------------------------------------
If the Gelfond–Schneider theorem is true:
then (-e)^e must be transcendental.
and (-e)^e is equal to [(-1)^e]*[e^e]
still if the theorem is true; e^e must be transcendental.
then assume 1 from the above conjecture is true:
there are 2 complex answers of (-e)^e
or assume 2 is true:
(-e)^e is undefined
so clearly either way, it is a paradox.


By Victor Lu, 16
Burnside High School, Christchurch, NZ
496200691@qq.com

Hey n_kelthuzad and welcome to the forums.

It might help you to realize the following identity:

Consider the same c = a^b number. If a < 0 then we can write this number as:

c = a^b = |a|^b x e^(ib) where |a| is the absolute value of a and y is known as the argument of the complex number which is given by calculating:

The way you can interpret is that if you graph two functions corresponding to the real part of c and the imaginary part, then you'll get something that looks like a wave but it will either keep increasing or decreasing as the b value increases. I'm assuming also that b is a real number.

If you are having trouble, then a normal sine or cosine wave is when a = -1. If -1 < a < 0 then the peak and the trough of the wave will go towards the x-axis as b goes to infinity. If a < -1 then the peak and the trough will go towards infinity.
 
chiro said:
Consider the same c = a^b number. If a < 0 then we can write this number as:

c = a^b = |a|^b x e^(ib) where |a| is the absolute value of a and y is known as the argument of the complex number which is given by calculating:

The way you can interpret is that if you graph two functions corresponding to the real part of c and the imaginary part, then you'll get something that looks like a wave but it will either keep increasing or decreasing as the b value increases. I'm assuming also that b is a real number.

If you are having trouble, then a normal sine or cosine wave is when a = -1. If -1 < a < 0 then the peak and the trough of the wave will go towards the x-axis as b goes to infinity. If a < -1 then the peak and the trough will go towards infinity.

c = a^b = |a|^b x e^(ib) ?

so if a= -1, b=2 c=1; then |-1|^2*e^(2i) = e^2i?
i suppose that can only be e^2i∏ which equals to 1.
and what's this formula called?
 
n_kelthuzad said:
c = a^b = |a|^b x e^(ib) ?

so if a= -1, b=2 c=1; then |-1|^2*e^(2i) = e^2i?
i suppose that can only be e^2i∏ which equals to 1.
and what's this formula called?
e^(ix) = cos(x) + i sin(x) where i is the square root of -1. In other words i = SQRT(-1) and i^2 = -1.

Here is some more information:

http://en.wikipedia.org/wiki/Euler's_formula
 

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