Besides what has been said in this post. You can also define a new "bigcdot" operator using `scalerel`

package, for example:

```
\documentclass{article}
\usepackage{amsmath,scalerel}
\DeclareMathOperator*{\Bigcdot}{\scalerel*{\cdot}{\bigodot}}
\begin{document}
\[\Bigcdot_{i=1}^\infty A_i=A_1+A_2+\cdots\]
\end{document}
```

gives you:

**EDIT:**

I considered some alternative solutions so I will post them here.

As one can see, a problem with the `scalerel`

solution is that it stretch the `\cdot`

too wide such that the symbol become less appeal (at least to me). So how do we get a smaller dot with bigger "size"? For instance, let's say we want to have the dot in `\bigodot`

(we can use `\boldsymbol{\cdot}`

for the dot only) without the circle, how do we do it?

Well, there are at least two ways: first, we want to declare this new symbol as a math operator, such that superscript and subscript will go directly above and below it, then we either enclose the bold cdot with a box of total height of `\bigodot`

, or we insert a invisible character of the size of `\bigodot`

after the bold cdot, as illustrate by the code (both do not need any package other than `amsmath`

):

```
\newsavebox\dotbox
\sbox{\dotbox}{\(\displaystyle\bigodot\)}
\DeclareMathOperator*{\bigcdot}{\raisebox{0pt}[\ht\dotbox][\dp\dotbox]{\(\boldsymbol{\cdot}\)}}
```

and

```
\newsavebox\dotbox
\sbox{\dotbox}{\(\displaystyle\bigodot\)}
\newlength{\dotheight}
\setlength{\dotheight}{\ht\dotbox}
\addtolength\dotheight{\dp\dotbox}
\DeclareMathOperator*{\bigcdot}{\boldsymbol{\cdot}\rule[-\dp\dotbox]{0pt}{\dotheight}}
```

That said, we can also redefine other "small" symbol, such as `\bullet`

and `\|`

, in similar ways. In the end, let's compare the results:

```
\[
\Bigcdot_{i=1}^\infty A_i=\bigccdot_{i=1}^\infty A_i=\bigcdot_{i=1}^\infty A_i=\bigodot_{i=1}^\infty A_i=\sum_{i=1}^\infty A_i
\]
```

The problem occurs because of a conflict between `classicthesis`

and the `fourier`

package, which is loaded because you've set Utopia as the Roman font. Set the Roman font to Default in Document --> Settings --> Fonts, and things should work fine.

## Best Answer

Here are the possibilities with

`amssymb`

: