This is a Machlokes between the Turei Even and the Minchas Chinuch. The Turei Even says that two people can be Mekayem their Chiyuv by bringing the Chagigah together, whilst the Minchas Chinuch maintains that they cannot.

1) The Turei Even is in Chagigah 6a (DH ha'Re'iyah). He writes that a few partners may join together and bring a Korban Chagigah as long as each partner owns a share worth a Perutah. This is the Din mid'Oraisa, but mid'Rabanan the Din is that each partner must own at least "Shtei Kesef," the value of two silver coins of the Chagigah (see Chagigah 7a: "veha'Chagigah Shtei Kesef").

The Turei Even writes at length to cite proofs that the Chagigah may be brought by partners. One of the proofs is the fact that the Gemara (Chagigah 7a) states that the value of the Korban Re'iyah must be one Ma'ah (a silver coin). We know, however, that the Korban Chagigah must be an animal (see Pesachim 69b). The Turei Even asserts that it is not possible to buy an animal for so cheap as one Ma'ah. Therefore, it must be that the animal is purchased in partnership, and in this way it is possible that each partner owns the value of one Ma'ah in the offering.

Since the Gemara compares the Dinim of Olas Re'iyah to the Dinim of Chagigah, the Turei Even asserts that once we know that the Olas Re'iyah may be brought by partners, we also know that the Chagigah may be brought by partners.

2) The Minchas Chinuch (Mitzvah 88:1, in Kometz Minchah) disagrees with the Turei Even. His proof is from Rashi in Pesachim 89b (DH v'Al Chagigoso). The Gemara there discusses a person who appoints others to own a Chagigah together with him. Rashi writes that this refers to the Chagigah brought on the 14th of Nisan, because this Korban may be brought in partnership by all of the partners. The Minchas Chinuch asserts that Rashi implies that it is only the Chagigah brought on the 14th of Nisan which may be brought by partners, while the Chagigah brought on every day of the Yom Tov may not be offered by partners, and they would not fulfill their Chiyuv if two people brought the Korban Chagigah together.

It requires further study to decide which points in this dispute fit better with the Minchas Chinuch, and which better with Turei Even. However, I will close here.

Kol Tuv,

Dovid Bloom

I found that the Netziv, in Meromei Sadeh to Chagigah 6a, also disagrees with the Turei Even and holds that two people cannot bring a Chagigah together.

1) The Netziv rejects the proof of the Turei Even -- that since the Gemara says that the minimum value of a Chagigah is a Ma'ah, this must mean that more than one person is bringing it because there is no an animal which is only worth a Me'ah. The rejection of this proof is from Bechoros 11a, where the Gemara tells us that there is a very cheap animal which is possible to bring as a korban. This is a "Pitroza bas Danka." Rashi explains that this is a thin, weak sheep which is worth only a Ma'ah. We see from the Gemara that there are animals which indeed are so cheap, so it could be that the animal referred to in Chagigah 7a is such an animal, and if so there is no proof from there that partners can bring a Chagigah together.

2) The Meromei Sadeh also writes that it is logical that partners cannot bring a Chagigah together. This is because it is an obligation to bring a Korban Chagigah, and thus it is logical to say that each individual has to bring his own personal Chagigah to fulfil this obligation, and it does not sufficeto join with someone else.

3) The Meromei Sadeh cites another proof that one cannot bring a Chagigah b'Shutfus. The proof starts on Temurah 2a where there is an opinion that according to Rebbi Yehudah one never does the process of Semichah (leaning on the Korban) on a Korban that is brought by partners. The Meromei Sadeh then refers us to Beitzah 20a, where we learn that according to Shamai one may not do Semichah on Yom Tov. It follows that one does not bring a Chagigah on Yom Tov. The Meromei Sadeh then cites the Talmud Yerushalmi 2:4 which relates that one Yom Tov, Ben Buta entered the courtyard of the Beis ha'Mikdash and found it empty since no one was able to bring their Korban due to the prohibition against doing Semichah on Yom Tov.

The Meromei Sadeh asks: Why was the courtyard empty? Why did everyone not get together with their friends and bring a joint Chagigah? If one brings any joint Korban, one does not have to do Semichah according to Rebbi Yehudah, so this should be a good way to make it possible to bring the Chagigah on Yom Tov!

The Meromei Sadeh concludes that the reason why they did not implement the above idea must be because two people may not bring a Chagigah together, and this explains why Ben Buta found the Azarah so empty.

Kol Tuv,

Dovid Bloom

Up to now we have seen sources from Acharonim about bringing a Chagigah with others, but there in fact is a source in Chazal that one may bring a Chagigah b'Shutfus, which would seem to be a very strong support for the Turei Even cited above.

The source is the Tosefta, Chagigah 1:6, which reads: "What is a Chagigah? These are Shelamim that come for a Chagigah. If a person is able to bring this from his own house, he should bring it. Otherwise, he may join with others [to bring the Chagigah] as long as his share in the animal is not worth less than the minimal obligatory sum. Whether he brings his own animal or he brings together with others, in both ways he has fulfilled the Mitzvah."

This Tosefta explicitly states that people may bring a Chagigah together to fulfill their oblgiation. It certainly is surprising that the Acharonim did not mention this Tosefta, and, in addition, we now have to find a way to reconcile this with the arguments of the Acharonim who asserted that a Chagigah may not be brought b'Shutfus.

Maybe we will come back to this at some later stage.

Kol Tuv,

Dovid Bloom