Skip to main content Accessibility help
×
Hostname: page-component-848d4c4894-xm8r8 Total loading time: 0 Render date: 2024-06-16T15:02:35.711Z Has data issue: false hasContentIssue false

Chapter 15 - Freeness under Hadamard products

from Part III - Structure theory for bimonoids

Published online by Cambridge University Press:  28 February 2020

Marcelo Aguiar
Affiliation:
Cornell University, Ithaca
Swapneel Mahajan
Affiliation:
Indian Institute of Technology, Mumbai
Get access

Summary

In this chapter, we study further the Hadamard product on species. The Hadamard product of two free monoids is again free. Similarly, the Hadamard product of two free commutative monoids is again free commutative. In either case, we give an explicit formula for a basis of the Hadamard product in terms of bases of its two factors. It involves the meet operation on faces and flats, respectively. We also show that the Hadamard product of bimonoids is free as a monoid if one of two factors is free as a monoid. We study in detail the Hadamard product of the free bimonoid on a comonoid with the cofree bimonoid on a monoid. It is neither commutative nor cocommutative, so Borel-Hopf does not apply. This bimonoid is both free and cofree. Interestingly, we prove this using Loday-Ronco (which is a theorem about 0-bimonoids). We also give a cancelation-free formula for its antipode. We give an explicit description of its primitive part, and more generally, its primitive filtration. An illustrative example of this construction is the bimonoid of pairs of chambers. We give a parallel discussion for a commutative counterpart where we take the Hadamard product of the free commutative bimonoid on a cocommutative comonoid with the cofree cocommutative bimonoid on a commutative monoid. (Since this bimonoid is bicommutative, it can also be tackled using Leray-Samelson.)

Type
Chapter
Information
Publisher: Cambridge University Press
Print publication year: 2020

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Save book to Kindle

To save this book to your Kindle, first ensure coreplatform@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.

Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

Find out more about the Kindle Personal Document Service.

Available formats
×

Save book to Dropbox

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.

Available formats
×

Save book to Google Drive

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.

Available formats
×