Help with namespaces in xpath (PostgreSQL 9.5.3)

I have an xml document from which I would like to extract the contents of
several elements.

I would like to use xpath to extract the contents of "name" from the xml
document shown below.

WITH x AS
(
SELECT
'<?xml version="1.0" encoding="UTF-8"?>
<uniprot xmlns="http://uniprot.org/uniprot" xmlns:xsi="
http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="
http://uniprot.org/uniprot http://www.uniprot.org/support/docs/uniprot.xsd">
<entry dataset="Swiss-Prot" created="2009-12-15" modified="2016-05-11"
version="56">
<accession>A0JM59</accession>
<name>UBP20_XENTR</name>
</entry>
</uniprot>
'::xml AS d
)
SELECT (xpath('/uniprot/entry/name/text()',a.d))[1]::text AS uniprot_name
FROM
x AS a
;

The documentation for xpath() ("
https://www.postgresql.org/docs/9.5/static/functions-xml.html") describes
"xpath(xpath, xml [, nsarray]").

For the above xml document, what would be the two dimensional array
"nsarray" for the xpath() function?

-Allan.