What will be the form of the \$k^{th}\$ component of \$x^{(i)}\$?

In summary, we discussed indexing the components of elements in $\mathbb{Z}_p$ by subscripts and the terms of a sequence by superscripts. We concluded that if a sequence is in $\mathbb{Z}_p$, it will be a sequence of p-adic integers, and the $k^{th}$ component of $x^{(i)}$ will be the coefficient of $p^k$. We also clarified that the definition of $\mathbb{Z}_p$ we are using is a sequence of elements in $\mathbb{Z}/p^{k+1}$ that satisfy the property $x_{k+1} \equiv x_k \mod{p^{k+1}}$.
  • #1
evinda
Gold Member
MHB
3,836
0
Hi! (Smile)

Suppose that we index the components of the elements of $\mathbb{Z}_p$ by subscripts.

Indexing the terms of the sequence by superscripts in parentheses$x^{(i)}$ is a term of the sequence, and $x^{(i)}_k$ its $k$-th component.
So, if we have a sequence in $\mathbb{Z}_p$, it will be like that, right?

$$x=(x^{(1)}, x^{(2)}, \dots, x^{(k)}, \dotsc)$$

What will be the form of the $k^{th}$ component of $x^{(i)}$ ? (Thinking)
 
Mathematics news on Phys.org
  • #2
evinda said:
Hi! (Smile)

Suppose that we index the components of the elements of $\mathbb{Z}_p$ by subscripts.

Indexing the terms of the sequence by superscripts in parentheses$x^{(i)}$ is a term of the sequence, and $x^{(i)}_k$ its $k$-th component.
So, if we have a sequence in $\mathbb{Z}_p$, it will be like that, right?

$$x=(x^{(1)}, x^{(2)}, \dots, x^{(k)}, \dotsc)$$

What will be the form of the $k^{th}$ component of $x^{(i)}$ ? (Thinking)

Hey! :eek:

I think it will be like:
$$x^{(1)} = (x^{(1)}_1, x^{(1)}_2, x^{(1)}_3, ..., x^{(1)}_k, ...)$$
(Thinking)
 
  • #3
I like Serena said:
Hey! :eek:
(Happy)

I like Serena said:
I think it will be like:
$$x^{(1)} = (x^{(1)}_1, x^{(1)}_2, x^{(1)}_3, ..., x^{(1)}_k, ...)$$
(Thinking)

So does this mean that each term of the sequence will be a sequence? (Thinking)
 
  • #4
evinda said:
So does this mean that each term of the sequence will be a sequence? (Thinking)

What is $\mathbb Z_p$?

Are those p-adic numbers or integers modulo p? (Wondering)

If they are p-adic numbers, then the sequence is probably as you thought, and
$$x^{(1)} = x^{(1)}_0 + x^{(1)}_1 p + x^{(1)}_2 p^2 + ...$$
(Thinking)
 
  • #5
I like Serena said:
What is $\mathbb Z_p$?

Are those p-adic numbers or integers modulo p? (Wondering)

It is the set of integer p-adics.. (Nod)

I like Serena said:
If they are p-adic numbers, then the sequence is probably as you thought, and
$$x^{(1)} = x^{(1)}_0 + x^{(1)}_1 p + x^{(1)}_2 p^2 + ...$$
(Thinking)

Could you explain me how we conclude that $x^{(1)} = x^{(1)}_0 + x^{(1)}_1 p + x^{(1)}_2 p^2 + ...$ ? (Thinking)
 
  • #6
evinda said:
It is the set of integer p-adics.. (Nod)

Could you explain me how we conclude that $x^{(1)} = x^{(1)}_0 + x^{(1)}_1 p + x^{(1)}_2 p^2 + ...$ ? (Thinking)

Let's take a closer look at your statements. (Thinking)

evinda said:
Suppose that we index the components of the elements of $\mathbb{Z}_p$ by subscripts.

Any p-adic integer $r \in \mathbb{Z}_p$ can be written as:
$$r = \sum_{i=m}^\infty a_i p^i$$
where $m \in \mathbb Z$ and $a_i \in \{0, ..., p-1\}$.

I'm interpreting your statement as saying that those components are the $a_i$ values. (Thinking)

Indexing the terms of the sequence by superscripts in parentheses

Now it seems some kind of sequence is introduced.
However, it is not clear if:
  1. the sequence of $a_i$ is intended,
  2. or the sequence of terms $a_i p^i$,
  3. or if this is about some sequence of p-adic integers.

Can you clarify? (Wondering)
$x^{(i)}$ is a term of the sequence, and $x^{(i)}_k$ its $k$-th component.

From this statement it seems that a sequence of p-adic integers is intended.
If so, then that would mean that $x^{(i)} \in \mathbb Z_p$.

Then $x$ would be a sequence of elements in $\mathbb Z_p$, and your next statement would be correct. (Nod)

So, if we have a sequence in $\mathbb{Z}_p$, it will be like that, right?

$$x=(x^{(1)}, x^{(2)}, \dots, x^{(k)}, \dotsc)$$

What will be the form of the $k^{th}$ component of $x^{(i)}$ ? (Thinking)

Since $x^{(1)} \in \mathbb Z_p$, we can write it as:
$$x^{(1)} = \sum_{k=m}^\infty x^{(1)}_k p^k$$

So there!
If my assumptions are correct, the $k^{th}$ component of $x^{(i)}$ is the coefficient of the corresponding $p^k$. (Wasntme)
 
  • #7
I like Serena said:
Let's take a closer look at your statements. (Thinking)
Any p-adic integer $r \in \mathbb{Z}_p$ can be written as:
$$r = \sum_{i=m}^\infty a_i p^i$$
where $m \in \mathbb Z$ and $a_i \in \{0, ..., p-1\}$.

I'm interpreting your statement as saying that those components are the $a_i$ values. (Thinking)
Now it seems some kind of sequence is introduced.
However, it is not clear if:
  1. the sequence of $a_i$ is intended,
  2. or the sequence of terms $a_i p^i$,
  3. or if this is about some sequence of p-adic integers.

Can you clarify? (Wondering)

From this statement it seems that a sequence of p-adic integers is intended.
If so, then that would mean that $x^{(i)} \in \mathbb Z_p$.

Then $x$ would be a sequence of elements in $\mathbb Z_p$, and your next statement would be correct. (Nod)Since $x^{(1)} \in \mathbb Z_p$, we can write it as:
$$x^{(1)} = \sum_{k=m}^\infty x^{(1)}_k p^k$$

So there!
If my assumptions are correct, the $k^{th}$ component of $x^{(i)}$ is the coefficient of the corresponding $p^k$. (Wasntme)

I think that the following definition of $\mathbb{Z}_p$ is used:

$$\mathbb{Z}_p=\{ (\overline{x_k}) \in \prod_{k=0}^{\infty} \mathbb{Z}/p^{k+1}\mathbb{Z}| x_{k+1} \equiv x_k \mod{p^{k+1}}\}$$

So, does this mean that if $x=(x^{(1)}, x^{(2)}, \dots, x^{(k)}, \dots)$ and $x \in \mathbb{Z}_p$, then $x$ is a sequence of element of $\mathbb{Z}_p$ and the elements of the sequence $\in \mathbb{Z}/p^{k+1}$ and satisfy the property $x_{k+1} \equiv x_k \mod{p^{k+1}}$ ? (Thinking)
 

FAQ: What will be the form of the \$k^{th}\$ component of \$x^{(i)}\$?

1. What is the purpose of the \$k^{th}\$ component of \$x^{(i)}\$?

The \$k^{th}\$ component of \$x^{(i)}\$ represents the value of the \$k^{th}\$ feature in the \$i^{th}\$ data point. It is used to describe the characteristics of the data and can be used in various scientific analyses and models.

2. How is the \$k^{th}\$ component of \$x^{(i)}\$ calculated?

The calculation of the \$k^{th}\$ component of \$x^{(i)}\$ depends on the specific data and features being analyzed. In general, it involves measuring or quantifying the value of the \$k^{th}\$ feature in the \$i^{th}\$ data point.

3. Can the \$k^{th}\$ component of \$x^{(i)}\$ be negative?

Yes, the \$k^{th}\$ component of \$x^{(i)}\$ can be negative. This depends on the specific data and features being analyzed and the values they take on. For example, if the \$k^{th}\$ feature is a measurement of temperature, it can take on negative values.

4. How does the \$k^{th}\$ component of \$x^{(i)}\$ relate to other components and data points?

The \$k^{th}\$ component of \$x^{(i)}\$ is just one part of the overall data point \$x^{(i)}\$. It can be compared to other components within the same data point or to the same component in other data points. It can also be used in combination with other components to analyze relationships and patterns within the data.

5. Can the \$k^{th}\$ component of \$x^{(i)}\$ vary over time?

Yes, the \$k^{th}\$ component of \$x^{(i)}\$ can vary over time. This depends on the specific data being analyzed and the nature of the \$k^{th}\$ feature. Some features may have a constant value over time, while others may change over time. This variability is an important aspect to consider in scientific analyses and models.

Similar threads

Replies
1
Views
2K
Replies
1
Views
1K
Replies
10
Views
2K
Replies
1
Views
1K
Replies
4
Views
3K
Replies
2
Views
1K
Replies
16
Views
2K
Replies
3
Views
2K
Back
Top