To answer the question if there's scientific research on this topic - I wasn't able to find anything of value on an, admittedly, quite cursory Google Scholar search.

In fact, given the high element of subjectivity in 'finding a text sounding authoritative', I think this question may be more suitable for Writing.SE. However, since the question is heavily upvoted, and since it does indeed touch on the Psychological Sciences, I'll give my two-cents worth based on two non-scientific, non-peer-reviewed book quotes and a regular website entry.

Online Writing Training says:

One of the main reasons why the passive voice gets such a bad name is that many [] writers overuse it to make their writing seem more formal and authoritative. The result is often turgid, difficult-to-read prose. Take this example

Lebrun Jean-luc says in his book Scientific Writing 2.0: A Reader And Writer's Guide

[The] passive voice [] give[s] the paper a more authoritative disembodies voice,...

As a last example, William M. Vatavuk states in his book Marketing Yourself with Technical Writing: A Guide for Today's Professionals:

Maybe technical writers feel that that the passive voice is more formal, more professional sounding, and that it gives their writing a more authoritative ring...

I think that last quote is important: people feel that way, but it's entirely a subjective thing; some may find the passive voice boring, others may regard it as authoritative.

Short answer
I haven't found scientific literature on it. Non-scientific sources generally do seem to acknowledge that the passive voice radiates authority.

Background
To answer the question if there's scientific research on this topic - I wasn't able to find anything of value on an, admittedly, quite cursory Google Scholar search.

In fact, given the high element of subjectivity in 'finding a text sounding authoritative', I think this question may be more suitable for Writing.SE. However, since the question is heavily upvoted, and since it does indeed touch on the Psychological Sciences, I'll give my two-cents worth based on two non-scientific, non-peer-reviewed book quotes and a regular website entry.

Online Writing Training says:

One of the main reasons why the passive voice gets such a bad name is that many [] writers overuse it to make their writing seem more formal and authoritative. The result is often turgid, difficult-to-read prose. Take this example

Lebrun Jean-luc says in his book Scientific Writing 2.0: A Reader And Writer's Guide

[The] passive voice [] give[s] the paper a more authoritative disembodies voice,...

As a last example, William M. Vatavuk states in his book Marketing Yourself with Technical Writing: A Guide for Today's Professionals:

Maybe technical writers feel that that the passive voice is more formal, more professional sounding, and that it gives their writing a more authoritative ring...

I think that last quote is important: people feel that way, but it's entirely a subjective thing; some may find the passive voice boring, others may regard it as authoritative.

First off, I think this question may be more suitable for Writing.SE, and I wasn't able to find anything of value on an, admittedly, cursory Google Scholar search. But since the question is heavily upvoted, and it does indeed touches on the Psychological Sciences, I'll give my two-cents worth based on two non-scientific, non-peer-reviewed book quotes and a regular website entry.

Online Writing Training says:

One of the main reasons why the passive voice gets such a bad name is that many [] writers overuse it to make their writing seem more formal and authoritative. The result is often turgid, difficult-to-read prose. Take this example

Lebrun Jean-luc says in his book Scientific Writing 2.0: A Reader And Writer's Guide

[The] passive voice [] give[s] the paper a more authoritative disembodies voice,...

As a last example, William M. Vatavuk states in his book Marketing Yourself with Technical Writing: A Guide for Today's Professionals:

Maybe technical writers feel that that the passive voice is more formal, more professional sounding, and that it gives their writing a more authoritative ring...

I think that last quote is important: people feel that way, but it's entirely a subjective thing; some may find the passive voice boring, others may regard it as authoritative.

To answer the question if there's scientific research on this topic - I wasn't able to find anything of value on an, admittedly, quite cursory Google Scholar search.

In fact, given the high element of subjectivity in 'finding a text sounding authoritative', I think this question may be more suitable for Writing.SE. However, since the question is heavily upvoted, and since it does indeed touch on the Psychological Sciences, I'll give my two-cents worth based on two non-scientific, non-peer-reviewed book quotes and a regular website entry.

Online Writing Training says:

One of the main reasons why the passive voice gets such a bad name is that many [] writers overuse it to make their writing seem more formal and authoritative. The result is often turgid, difficult-to-read prose. Take this example

Lebrun Jean-luc says in his book Scientific Writing 2.0: A Reader And Writer's Guide

[The] passive voice [] give[s] the paper a more authoritative disembodies voice,...

As a last example, William M. Vatavuk states in his book Marketing Yourself with Technical Writing: A Guide for Today's Professionals:

Maybe technical writers feel that that the passive voice is more formal, more professional sounding, and that it gives their writing a more authoritative ring...

I think that last quote is important: people feel that way, but it's entirely a subjective thing; some may find the passive voice boring, others may regard it as authoritative.