Welcome to Paolo Lipparini's home page.
Willkommen. Bienvenues. Benvenuti.
Witajcie. ˇBienvenidos! Bem-vindos. Benibenius.
Dobró požálovat’.
Yo-koso.
Isten hozott.

e-mail: [the first 8 letters of my family name] (a t) axp.mat.uniroma2.it

Alternative (emergency) e-mail: lpppla01 (at ) uniroma2 (dot) it

informazioni per gli STUDENTI (only italian)

My main mathematical interests are Ultrafilters, General Algebra,
General Topology, Model Theory, Set Theory, Ordered Sets and Foundations
of Mathematics.

The suggested place for readers interested in my work is
arXiv.org
.
There you can find recent or otherwise unpublished material
and possibly extended versions of pubished material.

An updated list of published papers can be found
here
or
using
zbMath and
MathSciNet.
Journal-refs on arXiv.org are updated, too.

Here you can download some
manuscripts
(mostly older material not present
in arXiv),
a very short
curriculum (italiano, english)
and
slides
from some talks. You can also find
my
contact informations,
and some
(very disparate)
links.

For all of my works, an important
disclaimer
is in charge, regarding possible misuses
of the reference lists.

**Recent works**

Non-generators in extensions of infinitary algebras

*(NOT on ArXiv!)*

The Tschantz and the alvin higher conditions are
equivalent in congruence distributive varieties
*(NOT on ArXiv! Published on Algebra Universalis)*

*
(Universal algebra, a 4-ary
term variation on
arXiv:2001.06705
)
*

The non-equivalence of two definitions of selective
pseudocompactness

*
(Topology; variations on pseudocompactness)
(NOT on ArXiv!)
*

If every subalgebra of A^4 is congruence modular
then A satisfies the tolerance identity

$\Gamma^*\cap\Theta^*=(\Gamma\cap(\Theta\circ \Theta))^*$

(PDF)
(DVI)
(PS)

*
(Universal Algebra, no assumption on the variety)
*

Shortened and published as:
A local proof for a tolerance intersection property,
Algebra Universalis Vol. 54 (3) 273-277 (2005) -
external link to the published version.

**Older manuscripts and papers.**

- Scanned from the originals
(I plan to add more)

The compactness spectrum of abstract logics, large cardinals and
combinatorial principles

*
(Model Theory, Set Theory, Ultrafilters)
*

Bollettino U.M.I. (7) 4-B, 875-903 (1990).

Difference terms and commutators

*
(Universal Algebra, no assumption on the variety)
*

Unpublished, but occasionally quoted.

K. Kearnes
and
A. Szendrei
have obtained strong related results.
See
The relationship between two commutators .

Congruence identities satisfied in n-permutable varieties

*
(Universal Algebra, m-permutable varieties)
*

Bollettino U.M.I. (7) 8-B, 851-868 (1994).

About some generalizations of
($\lambda$, $\mu$)-compactness

*
(Model Theory, Set Theory, Ultrafilters)
*

Proceedings of the
5^{th} Easter Conference on Model Theory (Wendisch Rietz, 1987),
Seminarber., Humboldt-Univ. Berlin, Sekt. Math. 93, 139--141
(1987).

Reviewed
here
by Zentralblatt MATH.

- Other manuscripts.

A new proof that n-permutable varieties satisfy lattice identities
(DVI)

*
(Universal Algebra, m-permutable varieties)
*

This
proof does not use commutator theory.

Addendum to "Existentially complete closure algebras"

*
(Algebra, Topology)
*

- In italiano.

Logica Matematica e valore della scienza

Una breve introduzione alla teoria del commutatore in algebra generale

Problemi matematici risolti con metodi logici

ETICA DEGLI AUTOVALORI

Il Principio dei Calzini Spaiati
(in italiano, extended english summary)

Una breve introduzione all'algebra universale con argomenti scelti

(versione non definitiva, ma spero gia' leggibile)

**Slides and presentations**

Slides
and
abstract
of the talk at
Ultramath2008
,
Pisa, about decomposability of ultrafilters and applications to Topology,
Set Theory and Model Theory. For more details, see the AILA 2014 talk below.

Slides
of the talk at
XXIV Incontro di Logica
,
(Bologna february 2011)
about "ordinal compactness" for topological spaces.

More details on
arXiv:1012.4737
, appeared in print in
Filomat 2020, Volume 34, Issue 4, Pages: 1117-1145.

Slides
and
abstract
of the talk at
XXV Incontro di Logica (AILA meeting)
,
Pisa,
14-17 aprile 2014,
about "Weak and local versions of measurability"
(some inaccuracies might be present).

More details on
arXiv:1404.1586
.

Problems about the Jonsson distributivity spectrum
,
presentation for
XXVI Incontro di Logica (AILA meeting)
,
Padova 2017.

More details on
arXiv:1702.05353
.

Slides
of the talk at
PALS
Panglobal Algebra and Logic Seminar
,
March 2022, about
"Relative lengths of Maltsev conditions".

More details on
arXiv:1902.05995
.

** Some links**

Lettera aperta (ottobre 2016)
al Presidente del Consiglio
firmata da Ciro Ciliberto, Giuseppe Mingione, Giorgio Parisi e molti altri.

Music

La via matematica all'umorismo
(una raccolta di barzellette matematiche molto accurata. Altri link
qui)

ROARS
sito sui problemi dell'’universitŕ e della ricerca

** How to contact me**

You can write me at the following address:

[the first 8 letters of my second name]
(a t) axp (d ot) mat ( d ot) uniroma2 (d ot) it

Dipartimento di Matematica

Universita' di Tor Vergata

Viale della Ricerca Scientifica

I-00133 ROMA

(currently retired)

Arrivederci. See you. Auf Wiedersehen. Au revoir. Sayonara. Aloha. Hasta
luego. Até logo. A si biri.