Tuesday, March 27, 2007
Integer solutions for a circle, conjecture from surrogate factoring
Working through the mathematics for surrogate factoring I found that for circles
a^2 + b^2 = r^2
with an integer radius greater than 4, there will be at least one integer solution for non-zero a and b, only about 1/3 of the time. As an example to understand the conjecture consider the first four cases:
3^2 + 4^2 = 5^2
6^2 + 8^2 = 10^2
5^2 + 12^2 = 13^2
and
8^2 + 15^2 = 17^2
the first four such solutions over the space from 5 to 17, which is 13 numbers, so you have 4/13 and an almost perfect 1/3 of the cases.
That follows from surrogate factoring as adding one more congruence to a congruence of squares gives the following:
x^2 = y^2 mod T
you can let k = 2x mod T so
2x = k mod T, multiply both sides by k, to get
2xk = k^2 mod T
and now add back to the original congruence of squares to get
x^2 + 2xk = y^2 + k^2 mod T
and then add k^2 to both sides and get
(x+k)^2 = y^2 + 2k^2 mod T
so you relate every factorization of one composite a factorization of some other composite, which I call the surrogate.
Actually trying to use this idea to factor you need explicit equations:
(x+k)^2 = y^2 + 2k^2 + omega*T
And you can factor your target T by instead factoring 2k^2 + omega*T which I call the surrogate.
Notice that for ANY difference of squares the surrogate factorization exists.
Now the obvious question since you have to pick k and omega is, how likely are you to factor a given target composite T with your arbitrary choice of k and omega?
You have three possibilities with the two main congruences:
x^2 = y^2 mod T and k^2 = 2xk mod T
And with no reason to pick either possibility over the other, you get that last possibility about 1/3 of the time, which gives the circle conjecture mentioned above, which I just say is a conjecture to be fair.
It seems to me that the proof is obvious enough at this point, but for now I'll call it a conjecture.
a^2 + b^2 = r^2
with an integer radius greater than 4, there will be at least one integer solution for non-zero a and b, only about 1/3 of the time. As an example to understand the conjecture consider the first four cases:
3^2 + 4^2 = 5^2
6^2 + 8^2 = 10^2
5^2 + 12^2 = 13^2
and
8^2 + 15^2 = 17^2
the first four such solutions over the space from 5 to 17, which is 13 numbers, so you have 4/13 and an almost perfect 1/3 of the cases.
That follows from surrogate factoring as adding one more congruence to a congruence of squares gives the following:
x^2 = y^2 mod T
you can let k = 2x mod T so
2x = k mod T, multiply both sides by k, to get
2xk = k^2 mod T
and now add back to the original congruence of squares to get
x^2 + 2xk = y^2 + k^2 mod T
and then add k^2 to both sides and get
(x+k)^2 = y^2 + 2k^2 mod T
so you relate every factorization of one composite a factorization of some other composite, which I call the surrogate.
Actually trying to use this idea to factor you need explicit equations:
(x+k)^2 = y^2 + 2k^2 + omega*T
And you can factor your target T by instead factoring 2k^2 + omega*T which I call the surrogate.
Notice that for ANY difference of squares the surrogate factorization exists.
Now the obvious question since you have to pick k and omega is, how likely are you to factor a given target composite T with your arbitrary choice of k and omega?
You have three possibilities with the two main congruences:
x^2 = y^2 mod T and k^2 = 2xk mod T
- Neither is satisfied.
- They are both true for one prime factor or only some prime factors of T.
- They are both satisfied.
And with no reason to pick either possibility over the other, you get that last possibility about 1/3 of the time, which gives the circle conjecture mentioned above, which I just say is a conjecture to be fair.
It seems to me that the proof is obvious enough at this point, but for now I'll call it a conjecture.