Can the value of a be solved for in the infinite series convergence equation?

In summary, the equation (1/2)\Re \zeta(a-ui) = 0 has a solution of a=1/2 for u = 14.1347, where \zeta is the Riemann zeta function. This was determined through analysis and graphing, and it is likely that this solution only applies to the analytic continuation of the original series for a > 1.
  • #1
camilus
146
0
[tex]\sum^{\infty}_{x=1} \frac{cos(14.1347 \ln (x))}{x^{a}} = 0[/tex]

Is there a way to solve for a? I don't think so but maybe someone here will have an insight as to what to do..
 
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  • #2
This equation is

[tex](1/2)\Re \zeta(a-ui) = 0 [/tex]

for [tex]u = 14.1347[/tex], where [tex]\Re[/tex] signifies the real part, and [tex]\zeta[/tex] is the Riemann zeta function.

The attached picture shows the graph (I did it without the factor 1/2). The .mw file is the Maple code that generated this picture.

So [tex]a=1/2[/tex] looks like the solution. If we replace [tex]u=14.1347[/tex] by the nearby zero of the zeta function [tex]u = 14.134725141734693790\cdots[/tex] then the solution would be exactly [tex]a=1/2[/tex] of course.

Caveat. Probably the original series converges only for [tex]a > 1[/tex] , so my analysis applies only to the analytic continuation.
 

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  • #3
g_edgar said:
This equation is

[tex](1/2)\Re \zeta(a-ui) = 0 [/tex]

for [tex]u = 14.1347[/tex], where [tex]\Re[/tex] signifies the real part, and [tex]\zeta[/tex] is the Riemann zeta function.

The attached picture shows the graph (I did it without the factor 1/2). The .mw file is the Maple code that generated this picture.

So [tex]a=1/2[/tex] looks like the solution. If we replace [tex]u=14.1347[/tex] by the nearby zero of the zeta function [tex]u = 14.134725141734693790\cdots[/tex] then the solution would be exactly [tex]a=1/2[/tex] of course.

Caveat. Probably the original series converges only for [tex]a > 1[/tex] , so my analysis applies only to the analytic continuation.


OMG brilliant! Thanks! I realized this a few days ago, and just realized now that I realized it, and it looks a bit clearer now. weird.. but I am not complaining, thanks!
 

Related to Can the value of a be solved for in the infinite series convergence equation?

What is an infinite series?

An infinite series is a mathematical expression that consists of an infinite number of terms, each of which is added or subtracted to form the sum. It can be represented as a sum of terms, where each term is expressed as a function of the variable n.

How do you determine if an infinite series converges?

The convergence of an infinite series can be determined by evaluating its limit as the number of terms approaches infinity. If the limit is a finite number, the series is said to converge. Alternatively, the series can be tested for convergence using various convergence tests, such as the comparison test, ratio test, or integral test.

What is the difference between absolute convergence and conditional convergence?

Absolute convergence refers to the convergence of a series where the absolute values of its terms are considered. A series is absolutely convergent if the sum of the absolute values of its terms is finite. On the other hand, conditional convergence refers to the convergence of a series where the absolute values of its terms are not necessarily considered. A series is conditionally convergent if it is convergent but not absolutely convergent.

What are some real-world applications of infinite series convergence?

Infinite series convergence has various applications in fields such as physics, engineering, and economics. For example, in physics, infinite series are used to model physical phenomena such as electrical circuits and fluid dynamics. In economics, infinite series are used to model economic growth and investment strategies. Engineers also use infinite series to approximate solutions to complex problems in various fields.

What are some common mistakes to avoid when working with infinite series?

One common mistake is assuming that a series is convergent without properly testing for convergence. Another mistake is incorrectly applying convergence tests or using them on series that do not meet the necessary criteria. It is also important to be careful when manipulating infinite series algebraically, as this can sometimes lead to incorrect results. Additionally, it is important to be aware of the conditions of convergence for a particular series and to make sure they are satisfied before concluding that the series converges.

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