Q:

Can I use Apache software logos without explicit permission in my slides?

According to Apache Trademark Policy page, I can use Apache feather logo in my slides without asking permissions.

You needn't ask us for permission to use the Apache feather logo (the version published by us here ) on your own website solely as a hyperlink to www.apache.org or to an appropriate Apache project, or in other materials, such as presentations and slides,

In contrast, there is another rule for Apache Foo software. It does not include  "presentations and slides"

You needn't ask us for permission to use Apache's graphics logos (the versions published on individual project's websites) on your own website solely as a hyperlink to the specific Apache project website or to www.apache.org. All other uses of Apache Foo (and similar) graphic logos must be approved in writing by VP, Apache Brand Management, member of the Brand Management Committee, or the relevant Apache projects' VP.

Should I contact them to use logos in my presentation?

A:

You missed this important part of the Trademark Policy:

Unlike ASF's word trademarks (such as "Apache" and "Foo"), our graphic logos are also licensed to the public under the Apache License. That license permits you to create derivative works of those logos, as with any other Apache copyrighted work. However, trademark law does not allow you to apply any "confusingly similar" derivative logo to software if a relevant consumer would likely be confused by that use of that derivative logo.

Therefore you can use the logos in your slide deck under the Apache license alright without asking for permission. You could just add an Apache notice and a link on a trailing slide alright.

